Cash runway calculator for a small business: weekly, with decisions
Cash runway is how long your cash lasts at the current pace of money in and out.
Test this on 13 weeks with the free starter.
What are you deciding?
Tap any of these and watch the dashed line move. What each one assumes appears below the list.
Your numbers
Cash out per week should already include your fixed costs. Fixed costs only set the floor.
How this is calculated
Each week: balance = last week's balance + cash in - cash out. The chart shows 26 weeks.
Cash floor: two months of the monthly fixed costs you entered. Fixed costs are assumed to be inside "cash out per week" already; here they only set the floor.
Weeks of cash: the week the balance reaches zero, to one decimal. If it does not reach zero in 26 weeks, the pace of the last four weeks is carried forward. If cash is not falling, the gauge shows ∞ (and anything beyond a year is shown as 52+).
Weeks below the floor: how many of the 26 projected weeks end under the floor.
The decisions: Hire: 5,000 a month from week 4. Revenue drops 30%: cash in is 30% lower from week 1. Buy 20k inventory: one payment of 20,000 in week 2. Top client pays a month late: 45% of cash in for weeks 1 to 4 arrives in weeks 5 to 8. Collect 10 days faster: about 10 days of cash in arrives once, in week 1. Raise prices 15%: cash in is 15% higher from week 5 (invoices already sent keep the old price; no customers lost).
What this is not: a forecast of your business. It extends the numbers you type. The full workbook builds the 13 weeks line by line. Read the method.
Runs in your browser. Nothing you type is sent anywhere. A planning tool, not advice.
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- Runs in your browser
- No signup
- 26 weeks, 6 decisions
- A workbook, not an AI agent.
In short
Cash runway is how long your cash lasts at the current pace of money in and out. Dividing cash by monthly net burn gives a rough answer in months. This calculator works week by week over 26 weeks, so a late client or a tax payment shows up in the week it lands.
How to read the result
- Green: cash stays above the floor for all 26 weeks.
- Amber: cash never hits zero, but at least one week ends under the floor.
- Red: cash hits zero inside the 26 weeks. The chart marks the week.
"Weeks of cash" is the week the balance reaches zero. "Cash floor" is two months of the monthly fixed costs you enter. "Weeks below the floor" counts the projected weeks that end under it. The exact rules are on the method page.
Simple runway vs weekly runway
Simple runway. Cash divided by monthly net burn. Fast, and fine for a first look. What it misses: timing. A late client or a tax payment is averaged away, and it has no floor.
Weekly path. Cash balance each week, with the decisions you add. What it misses: it extends the numbers you type; it does not know your taxes.
Simulator demo, example numbers (cash 60,000; other sliders at their defaults): hire someone at 5,000 a month plus a 30% drop in sales leaves 30.2 weeks of cash and 23 of the 26 weeks under the 56,000 floor. Cash never hits zero, but the floor is breached for most of the half-year. A single average does not show that.
Try these five scenarios
- Hire someone5,000 a month from week 4.
- Revenue drops 30%Cash in is 30% lower from week 1.
- Hire and a 30% drop togetherThe two decisions combined.
- Top client pays a month late45% of cash in for weeks 1 to 4 arrives in weeks 5 to 8.
- Collect 10 days fasterAbout 10 days of cash in arrives once, in week 1.
What this calculator cannot do
- It extends numbers you type. It is not a forecast of your business.
- It does not know your taxes, payroll dates or one-off bills, except the decisions you switch on.
- It assumes steady weekly flows. The workbook builds the 13 weeks line by line.
From the calculator to a real forecast
The free starter is one 13-week tab: type your cash today and what you expect in and out each week. The full workbook adds the floor tied to a status, the weekly log, the scenario test and the working-capital view.
Questions
What is cash runway?
Cash runway is how long your cash lasts at the current pace of money in and out. It is usually shown in weeks or months.
How is it different from burn rate?
Burn rate is how much more cash goes out than comes in over a period. Runway is how long your cash lasts at that rate: cash divided by burn. This calculator also shows the week each change lands, not only an average.
What is a cash floor?
The level of cash below which you stop choosing and start reacting. In this calculator the floor is two months of the fixed costs you enter. In the workbook the number of months is a cell you can change.
Is it accurate?
It does exact arithmetic on the numbers you type, week by week. It is not a prediction. The result is only as good as the numbers and the decisions you give it.
Does it store my numbers?
No. The calculator runs in your browser and nothing you type is sent anywhere. It remembers your currency choice in your browser. A share link holds your numbers in the address after the # sign, and only exists when you press the button.
Related
Get the free 13-week starter
One 13-week tab. A standard .xlsx file, checked in Apple Numbers. Not yet checked in Excel or Google Sheets. It opens with an example business already filled in, so you can see the week its cash drops under the floor before you type a number. It shows your runway in weeks and the week your cash is lowest.
Download the starter (no email)- A 13-week cash line with the week your cash is lowest
- Your runway in weeks
- No account, no bank login
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