Free tools
Calculators built for UK readers
Every number has a source and a verified-on date, the formula is on the page, and nothing you type leaves your browser. For the tools we have reviewed rather than built, see tool reviews.
AI
LLM VRAM calculator
Will this model run on my GPU or Mac, how fast, and what is the cheapest UK hardware that fits?
Security
Password crack time and breach check
How long a password survives three attack models, and whether it has appeared in a breach, without the password leaving your browser.
AI
LLM API cost calculator (GBP)
What a month of API calls costs across providers, with caching and agent presets.
Computing
UK device running cost
What a PC, GPU, NAS or Mac costs to run in pence per day at the current Ofgem cap.
How we keep the numbers honest
- Each tool reads its prices and specifications from a dated data file, and the "assumptions and data" table on the page is rendered from that same file, so the text cannot drift from the calculator.
- Data older than 120 days shows a warning on the page until it is refreshed.
- The formula is written out in words on every page, with a worked example you can check by hand.
- No accounts, no cookies for the tools themselves, and nothing you type is sent anywhere, except where a page says so explicitly.