How do you track cash runway without a finance team?

I keep it simple. Runway is cash in the bank divided by average monthly burn, so I just need those two numbers up to date.

What I do: log every expense as it happens, mark the recurring ones (subscriptions, tools) so they're counted every month, and update my cash balance whenever it changes. Once a month I look at where the money went by category, and I look at the runway number every day.

The mistake I see is only tracking it when money gets tight. By then you've lost the time to fix it. I built this into Trenston because I wanted it to just be there without me thinking about it, but a spreadsheet works too if you stay consistent.

How do you do it?