How Runway, Net Burn and Total Cash are calculated
The exact formulas behind the cash cards on Dashboards, which accounts they count, and why Runway sometimes reads No cash burn.
Total Cash
Total Cash is the combined balance of all your bank accounts at the end of the period you picked.
It counts bank accounts only. Credit cards are not cash, so they are left out.
If you have a bank account in another currency, the card adds a line breaking the total down by currency. The total itself is in your books currency.
Net Burn and Net Cash In
Net Burn is how much more money left your bank accounts than came in during the period:
Net Burn = money out of your bank accounts − money into your bank accounts
It uses the same money in and money out as the Cash Flow card, so Net Burn is always Cash Flow's net with the sign flipped.
Transfers between two of your own bank accounts are left out, because they don't change your total cash.
Paying a credit card from a bank account counts as money out, because the cash leaves the bank.
When more money came in than went out, the card is titled Net Cash In and shows the amount with a +.
Runway
Runway is how long your cash lasts if you keep burning at your recent pace:
Runway = Total Cash at the end of the period ÷ average Net Burn of the last 3 periods
ZeraBooks takes the Net Burn of the period you picked and the two periods before it, and averages them. Averaging three periods keeps one large payment, like a big payroll, from swinging the result.
It divides Total Cash by that average and rounds to a whole number.
The unit follows the period you picked: months for a month, quarters for a quarter, years for a year.
The chart draws your cash for the last 12 periods, then projects the next 12 at the same average, stopping at zero. The note under the card says which average it used and over which periods, in the form "Projection uses average net cash flow of … /month (Jan–Mar)."
| Runway shows | Why |
|---|---|
| 7 months (or quarters, or years) | You are burning cash; this is how long it lasts at the average. |
| No cash burn | Over the last 3 periods, at least as much money came in as went out on average, so there is nothing to run out of. |
| No activity | There is no cash balance and no movement to measure yet. |
While the period is still running, the card is titled Live Runway because the current period's burn can still change.
Important: No cash burn means your bank balance grew. It doesn't mean you made a profit: a loan, an owner contribution or an opening balance also raise cash. Check profit on the Profit & Loss.
Gross Income
Gross Income is the total of your revenue and other income categories for the period, the same amounts as on the Profit & Loss. It isn't a cash figure: Net Burn and Cash Flow are the cards marked CASH.
Frequently Asked Questions
Does Total Cash include credit cards?
No. Total Cash counts bank accounts only. Card balances are money you owe, so they appear as liabilities on the Balance Sheet.
What is the difference between Net Burn and Net Cash In?
They are the same figure. The card is titled Net Burn when more money left your bank accounts than came in, and Net Cash In when more came in.
Why does Runway say "No cash burn"?
Your average Net Burn over the last three periods is zero or less, meaning cash grew. A business whose cash isn't falling has no runway to count down.
Why did my runway change when I switched from a month to a quarter?
Runway is measured in the unit you picked. With a quarter selected, ZeraBooks averages the last three quarters and reports runway in quarters.
Does moving money between my own bank accounts count as burn?
No. Transfers between two of your bank accounts are left out of Net Burn and Cash Flow, because your total cash doesn't change.
Why is Net Burn different from my net income?
Net Burn follows cash in the bank; net income follows the Profit & Loss. Loan payments, owner draws, card payments and money you haven't collected yet affect one and not the other.
What does "Live Runway" mean?
The period you picked hasn't ended yet, so its burn, and the runway built on it, can still change as more transactions arrive.
Learn more about AI-native general ledger: A double-entry ledger where statements become proven transactions.
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