Cash flow calculator.

Operating cash flow, free cash flow, runway, and burn rate. The numbers that decide whether you're around in 12 months — separate from whether you're profitable on paper.

Why cash flow is the metric that actually kills businesses.

Most companies don't fail because they're unprofitable — they fail because they ran out of cash. Watching cash flow weekly is the cheapest insurance you can buy.

  1. 01
    Profit ≠ cash.You can be profitable on paper and still go broke. Cash flow tracks what's actually in the bank.
  2. 02
    It's the #1 killer.82% of small business failures trace back to cash flow, not lack of profitability. Run it weekly, not quarterly.
  3. 03
    Runway = decisions.Knowing your runway is what turns 'we need to do something' into 'we have 7 months — here's the plan.'
  4. 04
    Forecasts beat reactions.A 3-month cash flow forecast catches problems while you still have options. Reacting at zero is reacting too late.

Calculate your cash flow.

Cash received from sales and operations in the period.

Salaries, rent, software, supplies — recurring costs to run the business.

One-off cash spent on equipment, property, or long-term assets.

Cash balance at the start of the period — needed for runway.

Use the same period for revenue and expenses.

Operating vs. free vs. margin.

  1. 01
    Operating cash flow.Revenue minus operating expenses. Shows whether the core business actually generates cash.
  2. 02
    Free cash flow.Operating cash flow minus capex. The real number — cash you can spend on growth, debt, or owners.
  3. 03
    Cash flow margin.(Operating cash flow ÷ revenue) × 100. Healthy is 10%+; excellent is 20%+.

The three cash flow categories.

A full cash flow statement splits movements into three buckets. This calculator focuses on operating + capex (the parts you control day-to-day), but the others matter for the full picture.

Operating Activities

Cash from day-to-day business operations

Revenue, expenses, working capital changes

Investing Activities

Cash spent on or received from investments

Equipment purchases, property, securities

Financing Activities

Cash from funding sources

Loans, equity raises, dividends, debt repayment

Common cash flow mistakes.

  1. 01
    Confusing profit with cash flow (profit ≠ cash)
  2. 02
    Not tracking cash flow separately from P&L
  3. 03
    Ignoring timing differences (revenue booked vs cash received)
  4. 04
    Not planning for seasonal fluctuations
  5. 05
    Tying up too much cash in inventory
  6. 06
    Offering payment terms that are too generous

How to improve cash flow.

  1. 01
    Invoice immediately and follow up on late payments
  2. 02
    Offer early payment discounts (2% for 10 days)
  3. 03
    Negotiate longer payment terms with suppliers
  4. 04
    Reduce inventory levels through just-in-time management
  5. 05
    Lease equipment instead of buying to preserve cash
  6. 06
    Use cash flow forecasting to predict and prevent shortfalls
  7. 07
    Implement subscription/recurring revenue models
  8. 08
    Collect deposits or milestone payments upfront

More finance calculators.

  1. Burn rate calculator

    Monthly burn and detailed runway analysis for startups.

  2. Break-even calculator

    When revenue covers all costs — the line between losing and making money.

  3. Profit margin calculator

    Gross, operating, and net margin benchmarks by industry.

  4. All business tools

    The complete collection of free calculators for startups, SaaS, and freelancers.

Managing cash flow in spreadsheets? Build something better.

If you're running your business off a brittle spreadsheet, that's a tool problem. I build custom dashboards, forecasting tools, and internal apps in Next.js — purpose-built for how your business actually works.

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Built by Taro Schenker — full-stack developer who works with startups and local businesses.