Free tool · UK 2026 rates
Cost of vacancy calculator.
What is that open engineering role costing you while it stays open? Enter the salary and how long it has been live. The result is your own numbers and the published UK employer on-costs, nothing estimated.
Calculator
What is this role costing you while it stays open?
Your numbers, simple arithmetic. Salary presets are our published London bands; change them to match your role.
Lost output is valued at the employed cost of the person who is not there, the most conservative measure; the real figure includes the work that never ships and the load on the rest of the team. Ready to close it faster? Get a tailored benchmark for this role. Enquiries go straight to the founders. ★ 5.0 from 24+ Google reviews.
How to read the result
The employed cost is what the person would cost you if they were in the seat: base salary plus employer National Insurance and the statutory pension contribution. Dividing that by 260 working days gives the value of one day of their output, which is the least an open role costs you for every day it stays open. The agency fee line is there so you can put the two numbers side by side: a search that closes two weeks sooner is often worth more than the fee itself.
For the full reasoning, read what it costs to hire a software engineer in the UK, and for the salary to enter, use our salary benchmarks or the UK tech salary statistics.
FAQ
About the calculator.
How does the calculator work out the cost of an open role?
It takes the base salary you enter and adds the two statutory employer on-costs: National Insurance at 15 per cent above the £5,000 secondary threshold and auto-enrolment pension at 3 per cent of the £6,240 to £50,270 qualifying band, about £1,321 a year. That employed cost is divided by 260 working days to give a daily figure, which is multiplied by the days the role has been open.
Why value lost output at the employed cost?
Because it is the most conservative defensible number. An employer was willing to pay that much for the work, so the work not being done is worth at least that. The true cost of a vacancy is usually higher: features that do not ship, revenue that slips, and the load carried by the rest of the team.
Where do the salary presets come from?
They are the midpoints of the London base-salary bands OpenSource publishes in its salary benchmarks, drawn from the searches we run for venture-backed startups and scale-ups. Change the salary field to match your own role; the presets are only a starting point.
Can I link to or embed this calculator?
Yes. Link to this page freely. If you quote a figure from it in an article, please attribute it to OpenSource with a link so your readers can run their own numbers.