Smart Business Math

Cash Flow Forecast Calculator

Project your cash balance forward with simple monthly inflows and outflows.

Calculator

Results

Ending cash

$35,000.00

Net cash per month

$2,500.00

Lowest projected cash

$20,000.00

Includes starting balance before month 1

What this means

Net cash is positive across the horizon on these inputs. Revisit if receivables slip or expenses bunch up.

Copy Summary to paste the write-up. Copy Link for the same numbers every time. No login, no setup—just copy and go.

MonthEnding cash
Month 1$22,500.00
Month 2$25,000.00
Month 3$27,500.00
Month 4$30,000.00
Month 5$32,500.00
Month 6$35,000.00

Cash Flow Forecast Summary

Each month, ending cash = prior cash + inflow − outflow. This calculator rolls that forward so you can spot thin months before they arrive.

Explanation

Net cash per month is average inflow minus outflow.

Ending cash is the balance after the full forecast window; lowest projected cash is the trough along the way (including start).

Business implication: hire and spend decisions should clear the lowest-cash month, not just the average month.

Step-by-step example

Start $20,000, inflow $12,000, outflow $9,500, for 6 months:

  1. Net: +$2,500/mo
  2. After 6 months: $20,000 + 6 × $2,500 = $35,000

Formula

Net monthly = Inflow − Outflow

Ending cash (month n) = Starting cash + n × Net monthly

Helpful tips

  • Stress-test with lower inflows (slow collections) before big commitments.
  • Use AR Days to see if inflow assumptions match how fast you actually collect.

FAQ

What is a cash flow forecast?

It estimates how cash changes over time from inflows (collections, sales) and outflows (expenses, payroll). This version uses average monthly amounts for a quick plan.

Is this the same as profit?

No. Profit is accounting income; cash flow tracks money in the bank. You can be profitable on paper and still run out of cash.

How detailed should my inputs be?

Use averages for a first pass. For fundraising or tight months, break large one-time items into the month they hit.

How accurate is this calculator?

It assumes constant monthly net cash. Seasonality and delayed receivables will change results—update often.

Related tools

Key terms

Cash flow

Definition. The movement of cash in and out of the business over a period—not the same as profit on paper.

In simple terms. You can be profitable and still short on cash if customers pay late or you buy inventory up front. Cash-flow views focus on timing.

Net cash flow = cash in − cash out (for the period)

Example. Invoicing $20,000 but collecting $8,000 while paying $12,000 in bills creates a cash squeeze despite strong sales.

Common mistake. Equating booked revenue with cash in the bank.

Related calculators. Cash Flow Forecast Calculator, Accounts Receivable Days Calculator

Related terms. Accounts receivable days, Burn rate, Runway

Accounts receivable days

Definition. How many days, on average, it takes to collect payment after a sale on credit.

In simple terms. Higher AR days mean more of your money sits in unpaid invoices. That affects runway and whether you need deposits or tighter terms.

AR days ≈ (accounts receivable ÷ revenue) × days in period

Example. If AR is $30,000 and monthly revenue is $45,000, AR days are roughly 20 on a 30-day basis (simplified).

Common mistake. Ignoring aging—averages can hide a few very late invoices.

Related calculators. Accounts Receivable Days Calculator, Invoice Due Date Calculator

Related terms. Cash flow, Invoice due date, Late fee

Burn rate

Definition. How fast a business spends cash—usually net monthly cash decrease when expenses exceed cash in.

In simple terms. Startups and early freelancers use burn to understand how aggressive spending is relative to cash on hand. Positive cash generation is the opposite of burn.

Burn rate ≈ monthly cash out − monthly cash in (when out > in)

Example. Spend $12,000 and collect $7,000 in a month → about $5,000 monthly burn.

Common mistake. Calling all expenses “burn” even when revenue covers them, or ignoring one-time cash events.

Related calculators. Burn Rate Calculator, Runway Calculator

Related terms. Runway, Cash flow

See all terms in the Glossary →

Notes & Assumptions

Simple rolling cash forecasts are a standard owner and founder cash discipline tool.

Last reviewed: July 2026