About Calculator.uk.com
At a glance
- What it is: an independent website of free online calculators.
- How many: 487 calculators in 9 categories, plus step-by-step calculation guides.
- Who it's for: anyone, anywhere. The site is free to use worldwide, with no account or sign-up.
- For website owners: every calculator can be embedded on another site for free.
- Cost: free. The site is supported by advertising.
Calculator.uk.com is an independent website that publishes free online calculators. Each one shows its answer together with the method behind it. Every calculator explains how it works and how to read the result, and names the formula, guideline or standard it is based on.
Despite the .uk.com address, the site is not just for UK users. Most calculators, such as maths, science, engineering, health, pet and farming tools, work the same wherever you are, and many accept both metric and imperial units. The finance section includes calculators for UK rules (income tax, National Insurance, stamp duty, ISAs) as well as US ones (401(k), IRA, FHA loans). Calculator.uk.com is not affiliated with HMRC, the NHS or any government body.
Calculator categories
| Category | Calculators | Covers |
|---|---|---|
| Finance & Business | 84 | loans and mortgages, savings and compound interest, investments and retirement (including US 401(k) and IRA), UK tax (income tax, National Insurance, stamp duty, VAT) and business margins |
| Math & Engineering | 133 | arithmetic, algebra, geometry and statistics, plus construction and engineering estimates such as concrete, fencing, roofing and machining |
| Science & Lab Tools | 83 | chemistry, biochemistry and molecular biology lab calculations such as dilutions, molecular weight and DNA concentration |
| General | 80 | unit and number conversions, plus everyday tools such as tip, fuel cost, GPA and grade calculators |
| Agriculture & Farming | 30 | fertiliser, seed and plant population, livestock, gestation, yield and grain storage |
| Animals & Pets | 30 | pet feeding and calories, pet age and size, and veterinary dosage by weight |
| Health & Fitness | 24 | BMI, BMR, TDEE, calories, macronutrients, body fat and fitness |
| Time & Date | 14 | date and age differences, durations, time zones and time cards |
| Medical & Pharmaceutical | 9 | body surface area, kidney function (GFR), pregnancy and due dates, ovulation and cycle tracking, and genetics (allele frequency) |
| Total | 487 |
You can search every calculator from the search box at the top of any page.
Calculation guides
Alongside the calculators, we publish guides that explain common calculations step by step, with worked examples:
Embeddable calculators for website owners
If you run a website, blog or intranet, you can add any of our calculators to your own pages for free. The Calculators for Your Site page generates a ready-to-paste embed code. Embedded calculators appear without our header, navigation or ads, with a small "Powered by Calculator.uk.com" link.
How calculators are built and checked
Every formula is taken from a named source, such as published scientific literature, professional or clinical guidelines, or official tax rules, and that source is named in each calculator's FAQ. Calculators are tested against known reference values before publication and are reviewed on a rolling basis. Read the full process on our methodology page. Results from financial, medical and veterinary calculators are estimates for information only, not professional advice.
Contact
Spotted an error, or have an idea for a calculator? Email hey@calculator.uk.com.