Free tool for startup and SaaS founders

How much runway goes on building the wrong thing?

Features rebuilt because the brief changed. Features shipped that nobody uses. Hours of copy-paste between tools. Put in your own numbers and see how many months of runway it adds up to. Two minutes, no email needed.

Your startup

Pick the closest fit. We pre-fill typical values for that stage. Change anything that doesn't match your reality.

Monthly burn your figure£k

Monthly spend on product and engineering your figure£k

In-house team, contractors and agencies: everyone who designs, builds and tests. Part of the burn above.

Development effort spent on rework planning assumption%

Rebuilding things because the requirement was unclear, changed mid-build, or was understood differently by the developer.

Shipped features that hardly anyone uses planning assumption%

Built, tested and released, then barely touched by users. Industry studies put this much higher. The default is cautious.

Team hours a week on manual ops planning assumptionhrs

Whole team. Copy-paste between CRM, billing and spreadsheets, reports built by hand, customers onboarded manually.

Loaded hourly cost planning assumption£/hr

Salary plus employer costs, divided by hours worked.

Where the runway goes, and how it comes back

Most waste starts before the first line of code: one idea explained five times, to five people, five slightly different ways. We fix the thinking first, then build only what has earned its place, on the tools you already pay for.

Step 1

Problem agreed

One page: who it's for, what job it does, how you'll know it worked. Signed off before design starts.

Step 2

Prototype tested

A clickable prototype in front of real users within days, so wrong ideas die cheaply and early.

Step 3

Spec the team can build

Flows, rules and edge cases written once, so developers build what you meant the first time.

Step 4

Ops on autopilot

CRM, billing and reporting connected, so the team stops being the glue between tools.

How we calculate it

Product spend    = monthly product spend × 12
Rework           = product spend × rework share
Unused features  = (product spend − rework) × unused share
Manual ops       = hours a week × 46 weeks × hourly cost
Total            = sum of the three, shown ±20%
Runway           = total ÷ monthly burn

Read this before you quote it

These are estimates from your inputs, not a forecast or a guarantee.
Typical values are planning assumptions for that stage. Your own figures will always be better.
Some unused features are the price of learning. The point is to learn it from a prototype, not from a release.
Time saved becomes runway only if you don't fill it with new hires. The year counts 46 working weeks.

Want a second pair of eyes on your roadmap?

In 30 minutes we go through your numbers and your next build, and tell you plainly what we would cut, test or automate first.

Book the review

Common
Questions

What is runway leak?

The part of a startup's burn that buys nothing it keeps: features rebuilt because the brief changed, features shipped that nobody uses, and team hours spent copying data between tools. The calculator shows it in pounds a year and in months of runway at your current burn.

Which costs does it include?

Three: rework (yearly product and engineering spend × rework share), unused features (the rest of that spend × unused share) and manual operations (hours a week × 46 weeks × hourly cost). Rent, marketing and salaries outside product and operations are not counted.

How often should founders recheck it?

After any change that moves your burn: a raise, a hiring round or a big roadmap change. Otherwise once a quarter is enough. It takes two minutes, so it fits into a board pack.