About CalcUK

CalcUK provides free, precision calculators for both the UK and US markets. Our growing library covers finance, health, tax, math, science, electrical engineering and unit conversions. Whether you are working out a mortgage repayment, estimating your take-home pay, tracking health metrics or converting units, every tool is designed to give you clear, accurate results in seconds.

Making complex calculations simple and accessible. Every calculator on CalcUK is completely free to use with no sign-up required, no fees charged and no personal data collected. We believe that everyone should have access to professional-grade tools without barriers.

All calculations run entirely in your browser. Nothing is sent to a server, stored in a database or shared with third parties. Your data stays on your device, always. Close the tab and it is gone. This approach means instant results with zero privacy concerns.

Our UK tools use official HMRC 2025/26 tax rates and thresholds. US tools use IRS 2025 rates. Every formula is industry-standard and cited, from Mifflin-St Jeor for metabolic calculations to standard amortisation for mortgage repayments. We update our rates at the start of each tax year so you always get current figures.

While our tools are built for accuracy, they are intended for guidance and estimation purposes. For decisions involving significant sums or personal health, we always recommend consulting a qualified professional.