Cash runway is the number of months a business can keep operating before cash runs out, based on current cash and monthly net burn. A simple version is cash on hand divided by monthly expenses minus monthly revenue.

What is net burn rate?

Net burn rate is monthly cash outflow after subtracting operating revenue from operating expenses. If expenses are lower than revenue, the business is not burning cash under the entered assumptions.

Does this replace a cash flow forecast?

No. This calculator is a quick planning estimate. It does not replace a full cash flow forecast with accounts receivable timing, debt payments, inventory purchases, taxes, or one-time costs.

Cash runway calculator

Estimate how many months your business can operate before cash runs out, then compare the result against revenue growth and expense changes.

Shows net burn, runway months, and an approximate depletion date.
Models steady, better, and tighter scenarios without storing your numbers.
Useful for founders, operators, freelancers, and small business finance reviews.

Runway worksheet Client-side estimate

Runway result

Months of runway6.3 months

Net burn / month$12,000

Cash depletion date—

StatusReview spending

How the runway math works

The quick formula is simple, but the monthly scenario loop helps when revenue or expenses are changing.

Core formula

Net burn = monthly expenses − monthly revenue. Cash runway = cash on hand ÷ net burn.

If revenue is already higher than expenses, the tool marks the business as cash-flow positive under the entered assumptions. If revenue or expenses change each month, the calculator steps through up to 120 months and stops when cash reaches zero.

Scenario checks to run before a hard decision

Runway gets more useful when you test the plan you hope for against the plan you can survive.

Base case

Use current monthly revenue and expense averages. Exclude owner draws or one-time purchases unless they repeat.

Tighter case

Raise expenses or lower revenue to see whether the business still has enough months to adjust.

Recovery case

Add realistic monthly revenue growth and check whether the business reaches break-even before cash runs out.

Example: service business with a six-month cushion

Use this as a quick sanity check for the default numbers.

Default example

A small agency has $75,000 in cash, $18,000 in monthly revenue, and $30,000 in monthly expenses. Its current net burn is $12,000 per month, so the simple runway is about 6.3 months before cash reaches zero. If revenue grows 2% per month and expenses stay flat, the month-by-month model gives a little more breathing room.

This is still a planning estimate. Real cash flow can change with customer payment timing, annual software renewals, inventory, debt payments, owner distributions, taxes, and seasonal sales.

Cash runway FAQ

Short answers for the decisions people usually make with runway numbers.

What is a healthy runway?

Many operators like at least 3 to 6 months of operating cash, while funded startups often plan for 12 to 18 months. The right cushion depends on sales cycle, payroll size, funding access, seasonality, and how quickly expenses can be reduced.

Should I use gross burn or net burn?

Use net burn for runway because it reflects expenses after revenue. Gross burn is still useful when you want to know the size of your monthly cost base before revenue.

What should I do if runway is short?

List the largest controllable expenses, unpaid invoices, committed revenue, and optional projects. Then test a tighter spending plan here before making hiring, marketing, or purchasing decisions.

Use these when runway decisions touch pricing, invoices, or hiring plans.