What is this site?
WhatToCharge.co.uk is a collection of free online calculators built for UK self-employed tradespeople — plumbers, electricians, builders, roofers, and every trade in between.
The tools help you answer the questions that matter most when you're running your own business:
- What day rate do I actually need to charge to hit my income target?
- Am I covering all my costs, or am I working for less than I think?
- How much will I actually take home after tax and National Insurance?
- How do I price this job properly — including materials, travel, and profit?
Why these tools are different
Most day rate calculators just ask "what salary do you want?" and divide by 260. That misses the point entirely.
Our calculators account for:
- Real overhead costs — van, insurance, tools, accountant, phone
- Non-billable time — holidays, sick days, training, admin, quoting time
- UK tax and NI — income tax bands and Class 4 NI for 2025/26
- Profit margin — the difference between breaking even and building a proper business
All calculators are updated annually for the new tax year and pre-filled with realistic defaults for each trade.
Who built this?
WhatToCharge.co.uk is an independent website with no connection to any other business, SaaS product, or paid service. It was built to give UK tradespeople access to proper financial tools without needing to sign up for anything or pay a subscription.
The site earns revenue through display advertising and affiliate links to trade insurance and accountancy software. These are clearly disclosed where relevant. We only link to products we'd recommend to a mate.
Accuracy & disclaimer
Tax rates are based on 2025/26 HMRC figures. We update the calculators each April at the start of the new tax year. While we make every effort to keep calculations accurate, these tools are for informational and guidance purposes only — they are not financial or tax advice. Always consult a qualified accountant for advice specific to your situation.