The Indie Hacker's Guide to Runway Math

Most solo founders track their bank balance and call it runway. That number lies to you.

The number that actually matters

Runway isn't "money in the bank." It's money in the bank divided by your actual monthly burn, including the expenses you forget: annual subscriptions averaged monthly, taxes you'll owe later, and your own living costs if you're not paying yourself a salary yet.

A simple monthly check

Once a month, write down three numbers: cash on hand, average monthly burn over the last quarter (not last month — one cheap month will lie to you), and expected revenue growth rate. Divide the first by the second, adjust for the third. That's your real runway.

Why this matters more once you have paying customers

Early revenue changes your risk tolerance in ways that feel good and are dangerous. A few hundred dollars in monthly recurring revenue can make founders relax on runway discipline right when they should be doing the opposite — extending runway is what buys you the time to find out if that early revenue is a trend or a fluke.