Cash Flow Calculator
The cash flow calculator finds your net cash flow by subtracting total outflows from total inflows over any time period. Enter your income sources and expenses — the calculator returns your net cash flow, monthly surplus or deficit, and annual projection instantly. No signup required, and it works for personal finances, small businesses, rental properties, and project budgeting.
Cash flow is the single most important number in any financial plan. A business can be profitable on paper and still fail because it runs out of cash before invoices are paid. A household can have a high income and still accumulate debt because outflows consistently exceed inflows. The cash flow calculator helps you see exactly where you stand — and what changes will have the biggest impact.
Whether you are planning a business budget, evaluating a rental property investment, managing your personal finances, or forecasting quarterly cash flow for a client presentation, this calculator gives you the clarity you need in seconds.
Also useful: our Break-Even Calculator finds the minimum revenue needed to cover your total costs, and our ROI Calculator measures the return on any investment or business expenditure.
Cash Flow Calculator
Calculate net cash flow across operating, investing & financing activities.
Operating Cash Flow
Calculate cash generated from your core business operations.
Free Cash Flow (FCF)
Cash left after operating expenses and capital expenditures.
What Is Cash Flow?
Cash flow is the movement of money into and out of a business, household, or investment over a specific period of time. Positive cash flow means more money is coming in than going out — the entity is accumulating cash reserves. Negative cash flow means more money is going out than coming in — the entity is drawing down reserves or taking on debt to cover the shortfall.
Cash flow is not the same as profit. Profit is an accounting concept that includes non-cash items like depreciation and accounts receivable — money owed to the business but not yet received. Cash flow measures actual money movement. A business can report strong profits while experiencing negative cash flow if customers are slow to pay invoices, if large capital expenditures were made, or if inventory was purchased in advance of sales.
This distinction is critical and widely misunderstood. Many businesses that fail do so not because they are unprofitable, but because they run out of cash before they can collect what is owed to them. “Revenue is vanity, profit is sanity, cash flow is reality” is a common saying in business finance for good reason.
Cash flow analysis is used for three main purposes: understanding the current financial health of a business or household, forecasting future cash needs to avoid running out of money, and evaluating investments by comparing the cash flows they generate against the cash invested to acquire them.
Cash Flow Formula
Net Cash Flow
Total Cash Inflows − Total Cash Outflows
A positive result means cash surplus — money left over after all outflows. A negative result means cash deficit — you are spending more than you are receiving and need to either cut outflows or increase inflows to cover the gap.
Example: A small business receives $28,000 in monthly revenue (inflow). Monthly expenses total $22,500 — including rent $4,000, salaries $12,000, supplies $2,500, utilities $800, insurance $400, subscriptions $300, and loan repayment $2,500. Net cash flow = $28,000 − $22,500 = $5,500 positive. The business generates $5,500 in cash surplus each month — $66,000 annually.
The Three Types of Cash Flow
In business accounting, cash flow is categorised into three types. Understanding which type you are measuring ensures you are calculating and interpreting the right number:
| Cash Flow Type | What It Includes | Positive Means | Negative Means |
|---|---|---|---|
| Operating cash flow | Revenue from sales, operating expenses, taxes paid | Core business generates cash | Core operations burn cash |
| Investing cash flow | Purchase or sale of assets, equipment, investments | Asset sales exceed purchases | Capital being deployed into growth |
| Financing cash flow | Loans received or repaid, equity raised, dividends paid | Net new funding received | Debt repaid or capital returned |
Net cash flow = Operating + Investing + Financing cash flows. A business can have negative investing cash flow (buying equipment) alongside positive operating cash flow (profitable operations) — this is normal and healthy for a growing business.
How to Use This Cash Flow Calculator
This cash flow calculator works for three scenarios. Choose the one that matches your situation:
Mode 1 — Business Cash Flow
Calculate monthly and annual net cash flow for a business. Enter all revenue sources as inflows and all operating expenses as outflows — the calculator returns your net cash flow, your operating surplus or deficit, and your annual run rate.
- Enter all monthly revenue sources: sales revenue, service income, rental income, interest, and any other inflows
- Enter all monthly operating expenses: rent, salaries, utilities, supplies, insurance, loan payments, subscriptions, and taxes
- The calculator returns monthly net cash flow, annual projection, and months of runway at the current burn rate
Example: Monthly revenue $45,000, monthly expenses $38,500. Net cash flow = $6,500 per month, $78,000 annually. If current cash reserves are $130,000, runway = $130,000 ÷ $6,500 = 20 months before reserves run out if revenue drops to zero.
Mode 2 — Personal Cash Flow
Calculate monthly net cash flow for personal finances. Enter all income sources and all regular expenses — the calculator returns your monthly surplus or deficit and shows where your money is going.
- Enter all monthly income: salary or wages, freelance income, rental income, investment returns, and any other regular inflows
- Enter all monthly expenses: housing, food, transport, utilities, insurance, debt repayments, subscriptions, and discretionary spending
- The calculator returns monthly surplus or deficit and the percentage of income spent in each category
Example: Monthly take-home income $5,800, total monthly expenses $4,950. Monthly surplus = $850, which represents 14.7% of income going to savings — healthy by most personal finance benchmarks.
Mode 3 — Rental Property Cash Flow
Calculate monthly and annual cash flow for a rental property investment. This is one of the most important calculations in real estate investing — a property that generates positive cash flow from day one is fundamentally different from one that requires ongoing top-up from the investor’s personal income.
- Enter monthly rental income and any other property income (parking, laundry, storage fees)
- Enter all monthly property expenses: mortgage payment, property tax, insurance, maintenance reserve, property management fees, vacancy allowance, and utilities paid by landlord
- The calculator returns monthly cash flow, annual cash flow, cash-on-cash return, and cap rate
Example: Rental income $2,200/month. Mortgage $1,100, property tax $250, insurance $120, maintenance reserve $100, property management $176 (8%), vacancy allowance $110 (5%). Total expenses $1,856. Monthly cash flow = $2,200 − $1,856 = $344. Annual cash flow = $4,128.
Cash Flow vs Profit — Key Differences
The difference between cash flow and profit is one of the most important concepts in business finance, and one of the most commonly confused. Many business owners monitor profit closely while being blindsided by cash flow problems — and vice versa.
| Aspect | Cash Flow | Profit |
|---|---|---|
| Definition | Actual money received minus actual money paid out | Revenue minus all expenses (including non-cash) |
| Timing | When cash actually moves | When revenue is earned or expense incurred (accrual) |
| Non-cash items | Not included (depreciation, amortisation) | Included (reduces profit without using cash) |
| Receivables | Only counted when collected | Counted when invoiced (accrual accounting) |
| Inventory | Counted when purchased (cash out) | Counted when sold (cost of goods sold) |
| Best used for | Operational survival, short-term planning | Business performance, tax reporting |
A practical example of the divergence: A consulting firm invoices $100,000 in December but the client pays in February. In December, the firm shows $100,000 in profit (accrual accounting) but $0 in cash received. If the firm has $80,000 in December expenses to pay, it has a $80,000 cash shortfall despite being “profitable.” This is why profitable businesses fail — and why cash flow monitoring is non-negotiable regardless of profitability.
What Is a Healthy Cash Flow?
The definition of healthy cash flow depends on the context — business type, industry, growth stage, and financial goals. Here are the key benchmarks used across common scenarios:
| Scenario | Healthy Cash Flow Indicator | Warning Sign |
|---|---|---|
| Small business (established) | Positive monthly operating cash flow; 3–6 months expenses in reserve | Consistently negative operating cash flow |
| Startup / growth phase | Negative cash flow acceptable if funded and tracking to profitability | Burning cash faster than projected with no clear path to positive |
| Personal finance | Saving 15–20% of take-home income monthly | Monthly deficit or saving less than 5% |
| Rental property | Positive cash flow after all expenses including vacancy | Cash flow negative without landlord top-up |
| Freelancer / self-employed | Positive cash flow after tax reserve (25–30%) set aside | Positive before tax but negative after — tax debt risk |
Cash flow adequacy is relative to reserves and obligations. Always evaluate cash flow in the context of available reserves and upcoming obligations.
Operating Cash Flow — The Most Important Number
Of the three types of cash flow, operating cash flow is the most critical indicator of business health. It measures how much cash the core business operations generate — before financing activities (loans, equity) and investing activities (equipment purchases, asset sales) are included.
Operating Cash Flow
Net Income + Non-Cash Expenses − Changes in Working Capital
For a simplified calculation without full accounting statements:
Simple Operating Cash Flow
Cash Revenue − Cash Operating Expenses
Operating cash flow is the number that determines whether a business can sustain itself without external funding. A business with positive operating cash flow can fund its own growth, repay debt, and build reserves. A business with negative operating cash flow is dependent on investors, lenders, or the owner’s personal funds to survive.
Investors and lenders pay close attention to operating cash flow because it is harder to manipulate than profit — revenue recognition timing and depreciation choices can significantly affect reported profit, but cash in and cash out is a factual record. Many professional investors use operating cash flow as their primary valuation metric, not earnings.
Free Cash Flow — What It Means
Free cash flow (FCF) is operating cash flow minus capital expenditures — the cash a business generates after maintaining and expanding its asset base. It represents the cash available to pay down debt, pay dividends, buy back shares, or reinvest in the business at management’s discretion.
Free Cash Flow
Operating Cash Flow − Capital Expenditures
Example: A manufacturing business generates $850,000 in operating cash flow but must spend $320,000 on equipment maintenance and replacement (capital expenditures) to maintain current production capacity. Free cash flow = $850,000 − $320,000 = $530,000. This $530,000 is genuinely available for discretionary use — the rest is consumed by keeping the business running.
Free cash flow is the basis for discounted cash flow (DCF) valuation — one of the most widely used methods for estimating the intrinsic value of a business. In DCF, projected future free cash flows are discounted back to present value using an appropriate discount rate, giving an estimate of what the business is worth today based on the cash it is expected to generate.
How to Improve Cash Flow
1. Accelerate Receivables Collection
The most immediate lever for improving business cash flow is collecting what you are owed faster. Every day an invoice sits unpaid is a day you are effectively lending money to your customer interest-free. Practical steps to accelerate collections: invoice immediately upon delivery of goods or services rather than at month-end; offer a small early payment discount (1% to 2% net 10) to incentivise fast payment; follow up on unpaid invoices systematically on day 1, day 7, and day 14 after the due date; and for new or high-risk customers, require partial payment upfront before beginning work.
Payment terms are negotiable. Many businesses default to 30-day payment terms without considering that shorter terms are entirely reasonable for their industry. Switching from net-30 to net-15 payment terms, if your customers accept it, immediately doubles the speed at which receivables convert to cash. Some industries routinely use net-7 or immediate payment — particularly in retail, hospitality, and professional services where customers pay at point of delivery.
2. Extend Payables Without Damaging Relationships
The counterpart to collecting receivables faster is paying your own bills as late as reasonably possible — within the agreed terms, without triggering late fees or damaging supplier relationships. If your suppliers offer net-30 terms, pay on day 30, not day 5. The extra 25 days of float are free working capital. If suppliers offer early payment discounts (2% net 10), evaluate whether the 2% discount is worth losing 20 days of cash float — at a 2% discount over 20 days, the annualised return on paying early is approximately 36%, making it almost always worth taking.
For large, recurring expenses, negotiate extended terms with your most important suppliers — particularly if you have a good payment history and are a significant customer. Moving from net-30 to net-45 or net-60 with key suppliers adds 15 to 30 days of cash float without any financing cost. Many suppliers will agree to extended terms for reliable, long-term customers who ask.
3. Reduce or Defer Capital Expenditures
Capital expenditures — purchases of equipment, vehicles, property, or other long-term assets — are major cash outflows that do not appear on the income statement in the period they occur (they are depreciated over time). Deferring non-essential capital expenditures by even one quarter can significantly improve short-term cash flow.
Where capital expenditures are necessary, evaluate leasing versus purchasing. Leasing converts a large upfront capital expenditure into a predictable monthly operating expense, preserving cash for operations. The total cost of leasing is typically higher over the life of the asset, but the cash flow benefit of spreading the outflow over time often outweighs the higher total cost for businesses with tight cash positions.
4. Optimise Inventory Levels
For product businesses, inventory is one of the largest cash flow drains. Every unit of inventory sitting unsold in a warehouse represents cash tied up and unavailable for operations. Excess inventory is a common cause of cash flow problems in otherwise profitable product businesses — the business is generating sales and recording profits, but the cash is locked up in stock.
Apply just-in-time inventory principles where your supply chain allows: order inventory to arrive as close as possible to when it will be sold or used. Track inventory turnover by SKU and identify slow-moving items — consider discounting or discontinuing products that turn less than 3 to 4 times per year in most retail and product businesses. Negotiate consignment arrangements with suppliers where possible, allowing you to hold inventory without paying until it sells.
5. Build and Maintain a Cash Reserve
The most reliable protection against cash flow crises is a cash reserve — liquid funds held specifically to cover unexpected shortfalls. For most businesses, the target cash reserve is 3 to 6 months of operating expenses. For seasonal businesses or those with irregular revenue, 6 to 12 months is more appropriate.
Building a reserve requires treating it as a non-negotiable expense rather than a residual — the amount left over after everything else is paid. Set a fixed monthly transfer to a dedicated reserve account as soon as the business generates positive cash flow, before any discretionary spending or owner distributions. A reserve of even one month of operating expenses significantly reduces the risk of a short-term revenue disruption causing a business failure.
Frequently Asked Questions
How do I calculate cash flow?
Subtract your total cash outflows from your total cash inflows over a specific period. Formula: Net Cash Flow = Total Cash Inflows − Total Cash Outflows. For a business, inflows typically include sales revenue, loan proceeds, and asset sales. Outflows include operating expenses, loan repayments, tax payments, and capital expenditures. A positive result means you generated more cash than you spent; a negative result means you spent more than you received. Use the cash flow calculator above to calculate your net cash flow instantly.
What is a good cash flow for a small business?
A good cash flow for a small business is consistently positive operating cash flow — the business generates more cash from operations than it spends. Beyond being positive, healthy small business cash flow should be sufficient to cover 3 to 6 months of operating expenses in reserve, fund ongoing growth without relying on external financing, and service any existing debt comfortably. As a rough benchmark, a healthy small business should aim for operating cash flow that is at least 10% to 15% of revenue — meaning for every $100 in revenue, at least $10 to $15 reaches the bank as available cash after expenses.
What is the difference between cash flow and profit?
Profit is the accounting result of revenue minus all expenses — it includes non-cash items like depreciation and accounts receivable (money owed but not yet received). Cash flow measures actual money movement — cash actually received minus cash actually paid out. A business can be profitable while experiencing negative cash flow if customers are slow to pay, if large capital purchases were made, or if inventory was built up in advance of sales. Conversely, a business can have positive cash flow while reporting an accounting loss if it is collecting old receivables or has significant depreciation charges. Both metrics matter, but cash flow determines whether a business can pay its bills today.
What is operating cash flow?
Operating cash flow is the cash generated by a business’s core operations — the revenue-generating activities that define what the business does — after paying all operating expenses. It excludes cash flows from investing activities (buying or selling assets) and financing activities (taking loans or repaying debt). Operating cash flow is the most important cash flow metric for evaluating business health because it shows whether the business can sustain itself without external capital. Positive operating cash flow means the business generates its own cash; negative operating cash flow means it depends on investors or lenders to survive.
What is free cash flow?
Free cash flow is operating cash flow minus capital expenditures — the cash a business generates after maintaining and growing its asset base. It represents the cash that is truly available to management to deploy at will: repay debt, pay dividends, buy back shares, make acquisitions, or invest in growth. Free cash flow is the basis for discounted cash flow valuation and is widely used by investors to assess business quality. A business that consistently generates strong free cash flow can fund its own growth and return capital to shareholders without needing external financing.
How do I improve my business cash flow?
The five highest-impact actions for improving business cash flow are: (1) invoice immediately and follow up systematically — the faster you bill and collect, the faster cash comes in; (2) negotiate longer payment terms with suppliers — every extra day before you must pay is free working capital; (3) reduce inventory to the minimum needed to meet demand — excess inventory is cash sitting idle; (4) defer non-essential capital expenditures or lease instead of buy; (5) build a cash reserve of 3 to 6 months of operating expenses so that short-term revenue disruptions do not become existential crises. Track your cash flow weekly, not monthly — a monthly review often catches problems too late to address them without pain.
What is a cash flow statement?
A cash flow statement is one of the three core financial statements (alongside the income statement and balance sheet) that shows all cash inflows and outflows during a reporting period, organised into three categories: operating activities, investing activities, and financing activities. The bottom line is the net change in cash — how much more or less cash the business has at the end of the period compared to the beginning. Cash flow statements are required in financial reporting for incorporated businesses and are reviewed closely by lenders, investors, and auditors. They are prepared using either the direct method (listing actual cash receipts and payments) or the indirect method (starting from net income and adjusting for non-cash items).
What is cash flow from investing activities?
Cash flow from investing activities includes all cash spent or received from the purchase and sale of long-term assets — equipment, property, vehicles, investments in other companies, and other capital items. It is typically negative for growing businesses because they are investing cash into assets to support growth. A large negative investing cash flow is not necessarily bad — it often signals the business is expanding capacity. It becomes concerning if investing cash flow consistently negative while operating cash flow is also negative, because the business is depleting cash on two fronts simultaneously without generating enough from operations to cover both.
How do I calculate monthly cash flow for a rental property?
Subtract all monthly property expenses from monthly rental income. Monthly expenses should include: mortgage principal and interest, property taxes (monthly equivalent), landlord insurance, maintenance reserve (typically 1% of property value annually, divided by 12), property management fees (typically 8% to 12% of rent), vacancy allowance (typically 5% to 8% of rent), and any utilities paid by the landlord. Example: Rent $2,000, mortgage $900, property tax $200, insurance $100, maintenance $150, management $160, vacancy $100. Total expenses $1,610. Monthly cash flow = $2,000 − $1,610 = $390. Annual cash flow = $4,680.
Can I use this cash flow calculator for personal finances?
Yes — this cash flow calculator works for personal finances, businesses, rental properties, and any other situation where you need to compare inflows to outflows. For personal use, enter all sources of income (salary, freelance, investments, rental income) as inflows and all regular expenses (housing, food, transport, utilities, subscriptions, debt payments) as outflows. The calculator returns your monthly surplus or deficit. A positive number means you are building wealth; a negative number means you are drawing down savings or accumulating debt and need to either increase income or reduce expenses.