All Tools Salary Calculator Bill Splitter Tip Calculator Percentage Loan Calculator VAT Calculator Compound Interest Discount | Unit Converter Date Calculator BMI Calculator Cooking Converter Age Calculator

Free Online Calculators

Fast, beautiful tools for everyday life. No sign-up required.

Financial

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Salary Calculator

UK take home pay after tax, NI, student loan & pension. 2025/26 rates.

Financial
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Bill Splitter

Split bills proportionally by income — fair for housemates and groups.

Financial
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Tip Calculator

Calculate tips with any percentage and split between your group.

Financial
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Percentage Calculator

Find X% of Y, what percent X is of Y, or calculate percentage change.

Financial
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Loan Calculator

Monthly repayments, total interest, and full amortisation schedule.

Financial
VAT

VAT Calculator

Add or remove VAT at 20%, 5%, or any custom rate instantly.

Financial
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Compound Interest

See how savings and investments grow over time with compound returns.

Financial
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Discount Calculator

Find the sale price and how much you save for any % off.

Financial

Everyday & Health

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Unit Converter

Length, weight, temperature, volume, area, speed, and data storage.

Everyday
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Date Calculator

Days between dates, or add and subtract days, months, years.

Everyday
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BMI Calculator

Calculate your Body Mass Index in metric or imperial.

Health
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Cooking Converter

Convert cups, tablespoons, ml, grams, and oven temperatures.

Everyday
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Age Calculator

Your exact age in years, months, days, hours, minutes.

Everyday

Frequently Asked Questions

Multiply the number by the percentage and divide by 100. For example, 15% of 200 = 200 × 15 ÷ 100 = 30. Our percentage calculator handles three operations instantly.
Divide each person's income by the total combined income, then multiply by the bill amount. Our bill splitter does this for any number of people.
Using the formula M = P × [r(1+r)^n] / [(1+r)^n – 1]. Our loan calculator does this instantly and shows a full amortisation schedule.
In the UK, 10–12.5% is standard. In the US, 15–20% is typical. Our tip calculator lets you choose any percentage and split between your group.

KwikSum is a free collection of online calculators for everyday life. Each tool is its own page for fast, focused results — percentage, bill split, tip, loan, VAT, compound interest, discount, unit converter, date, BMI, cooking converter, and age calculator. No sign-up, instant results, works on any device.