Interactive tool · Free · Updated for 2026

Cash Flow Calculator

See operating, investing, financing cash flow — plus runway and closing balance.

A small-business cash flow statement on one screen. Operating activities (collections, payroll, vendors), investing (capex), financing (loans, draws, debt service), and the net change in cash.

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4.9 / 5 · 730 ratingsUsed by founders and small-business ownersOperating + investing + financing cash flows
Live calculation
runs locally
Cash in
Cash out
Net cash flow
$4.1K
positive
Closing cash
$69.1K
from $65.0K
Operating cash flow
$20.5K
core engine
Runway
cash-positive
Headline
Net cash flow
$4.1K
growing
Headline
Runway
sustainable
Closing cash
$69.1K
end of period
Cash conversion
24%
operating CF / collections
Three streams
Operating + investing + financing = net
Statement of cash flows

Where the cash actually went.

Line item
In
Out
Customer collections
$85.0K
Payroll
$38.0K
Suppliers / COGS
$14.0K
Rent / utilities / software
$8.3K
Marketing
$4.2K
Capital expenditures
$6.0K
Financing in
Debt service / draws
$10.4K
Shareable

Share your prepayment plan.

Built for screenshots, partner conversations, and the occasional WhatsApp humble-brag.

lazysmirkcash-flow-calculator
Cash flow
$4.1K
cash-positive · closing $69.1K.
Operating
$20.5K
Investing
$-6.0K
Financing
$-10.4K
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Quick Answers

Cash Flow, in 30 seconds.

Direct answers to the most common questions, in plain language. Skim if you're in a hurry; dig deeper below.

What is cash flow?

Answer

Cash in minus cash out over a period.

Cash flow is the actual movement of money — not profit. Revenue is recorded when earned; cash is recorded when received. A profitable business can have negative cash flow if customers pay slowly.

What's the difference between profit and cash flow?

Answer

Profit is accrual; cash flow is actual.

Profit (net income) includes non-cash items (depreciation), uncollected revenue (receivables), and unpaid expenses (payables). Cash flow tracks the actual bank balance. Businesses die from poor cash flow even with strong profit.

What are the three types of cash flow?

Answer

Operating, investing, financing.

Operating: from running the business (collections, payments). Investing: buying/selling assets (equipment, property). Financing: loans, equity raises, dividends. Total = net change in cash for the period.

Why does cash flow matter?

Answer

Cash pays bills; profit doesn't.

"Cash flow is what keeps the lights on." A business with $500k profit and $0 cash can't make payroll. A business with $0 profit and $200k cash can. Cash flow is the survival metric; profit is the long-term metric.

How it works

How cash flow works.

The mechanics in short answers — no jargon, no upsell.

01

Start with operating activities.

Cash collected from customers minus cash paid to suppliers, employees, and overhead. The core engine.

02

Add investing activities.

Cash spent on equipment, property, software (usually negative). Add cash from selling assets if applicable.

03

Add financing activities.

Cash from new loans, owner contributions, equity raises (positive). Cash paid for loan principal, owner draws, dividends (negative).

04

Sum to net change in cash.

Operating + investing + financing = net change in cash. Add this to opening balance to get closing cash.

How to use

Four steps. About 20 seconds.

Designed so anyone can model their situation in under a minute, with or without a finance background.

  1. Step 1
    Enter cash inflows
    Customer collections, loan proceeds, owner contributions.
  2. Step 2
    Enter cash outflows
    Payroll, suppliers, rent, equipment, debt payments.
  3. Step 3
    See net cash flow
    Plus monthly burn rate and runway.
  4. Step 4
    Project forward
    See cash position at month 3, 6, 12 at current rate.
Benefits

Why this matters.

Operating cash flow

Cash generated from running the business.

Investing cash flow

Cash for assets — usually negative for growing businesses.

Financing cash flow

Cash from loans, investments, owner draws.

Net change in cash

The bottom line — did your bank account grow or shrink?

Runway calculation

How many months you have at current burn.

Quick monthly snapshot

Drop-in numbers from your bank and P&L.

FAQ

Cash Flow, answered.

Everything you might ask before, during, or after using this tool.

Written for borrowers, not bankersPlain-language, jargon-freeReviewed quarterly
How is cash flow different from revenue?

Revenue is what customers owe you (booked when sales close). Cash flow is what they've actually paid. Businesses with net 60 payment terms can have 2 months of "revenue" with $0 cash. The gap (accounts receivable) is invisible on a P&L but critical to cash flow.

What is burn rate?

Monthly negative cash flow — the rate you're consuming cash. A startup burning $50k/month with $300k in the bank has 6 months of runway. Burn rate × runway tells you how long until you need more capital.

How do I improve cash flow?

Five levers: (1) faster customer payments (terms, deposits, late fees), (2) slower supplier payments (negotiated terms), (3) inventory reduction, (4) recurring revenue models, (5) financing line of credit as buffer.

Is positive cash flow always good?

Usually yes, but not if it comes from unsustainable financing (taking on debt to cover losses) or under-investment (skipping maintenance, R&D). Strong operating cash flow is the real signal of business health.

What is free cash flow?

Operating cash flow minus capital expenditures. The cash available after maintaining the business. Often the most useful number for valuing a business — what's actually distributable to owners.

Should I budget on cash flow or P&L?

Both, but cash flow drives survival. Build a 13-week rolling cash flow forecast — what comes in, what goes out, by week. Update weekly. This is the operational document. The P&L is the strategic one.

How often should I review cash flow?

Weekly for small businesses or anyone tight on cash. Monthly for stable businesses. Quarterly is too infrequent for most — surprises accumulate. The 13-week cash flow is the standard for actively-managed businesses.

What's the cash conversion cycle?

Days inventory outstanding + days sales outstanding − days payables outstanding. Measures how long cash is tied up in operations. Shorter = better. Negative (suppliers paid after customers collect) is the operational gold standard.

Profit vs cash — different worlds

Profit follows accrual accounting: revenue when earned, expenses when incurred. Cash follows the bank.

A business invoicing $100k of services in December (collected in February) shows $100k of revenue in December but $0 cash. The "profit" doesn't pay the December payroll.

Cash flow is the survival metric. Profit is the long-term-value metric. Both matter, in that order.

The three streams

Operating: cash from running the business. Should be positive for a sustainable business.

Investing: usually negative for growing businesses (buying equipment, software, property).

Financing: positive when raising capital, negative when paying it back or distributing to owners.

A healthy business has positive operating cash flow large enough to fund some investing and still return cash via financing.

Runway math

Runway = cash on hand ÷ monthly burn.

At $300k cash and $50k/month burn: 6 months runway. At 3 months remaining, you should be actively fundraising or cutting burn.

Always know your runway. Always.

The five levers

1. Customer payment terms — net 30 instead of net 60, deposits up front, automated billing.

2. Supplier terms — push payables out, negotiate net 60 or net 90.

3. Inventory — match production to actual demand, not forecast optimism.

4. Revenue model — recurring (subscription) beats project-based for cash predictability.

5. Line of credit — not for ongoing operations but as a buffer for genuine timing gaps.

Common cash-flow mistakes

  • Managing to the P&L instead of cash position.
  • Not knowing your runway.
  • Letting receivables age without aggressive collection.
  • Buying equipment when leasing preserves cash.
  • Treating a line of credit as operating capital.
Trust & transparency

How this tool behaves, and what it isn't.

Two short notes worth reading before you trust any number on this page.

Privacy

Calculations run locally in your browser.

Your loan amount, rate, and prepayment inputs never leave your device. No accounts, no cookies on your numbers, no analytics on the values you type. Disconnect from the internet and it still works.

  • No account required
  • No data stored or sent
  • Works offline
  • No third-party trackers
Disclaimer

Lazysmirk is a tools platform, not a financial institution.

We are not a bank, NBFC, advisor, broker, or distributor of any financial product. The numbers shown here are estimates for educational purposes only, based on the inputs you provide.

Results are not financial, legal, or tax advice. Please consult a qualified professional before any decision about your loan, investments, or personal finances. Actual loan terms and charges depend on your bank and individual circumstances.