Free Online Calculators
Free online calculators that run in your browser: percentages, VAT, discounts, rule of three and more. Fast, no sign-up.
Solve all kinds of calculations instantly with our free online calculators. Whether you need to work out a percentage, add or remove VAT, know what you will pay after a discount or solve a rule of three, here you have the right tool. All calculations happen in your browser: your data is never sent to any server.
🧮 Calculators (12)
Percentage Calculator
Calculate percentages quickly and easily. Discounts, increases, VAT and more.
VAT Calculator
Calculate VAT instantly: add it to a base amount or extract it from a total. With 4%, 10% and 21% rates.
Rule of Three
Solve the rule of three instantly. Calculate direct proportions quickly and for free.
Discount Calculator
Calculate the final price and savings of any discount instantly. Sales, promotions and percentage discounts.
Tip Calculator
Calculate the tip, the total and how much each person pays when splitting the bill. Free and no sign-up.
BMI Calculator
Calculate your Body Mass Index (BMI) and see your category: underweight, normal, overweight or obese. Free.
Net Salary Calculator
Calculate your net salary from gross in Spain: IRPF income tax and Social Security deductions. Free and up to date.
Compound Interest Calculator
Calculate compound interest on your savings and investments with monthly contributions and an annual breakdown.
Mortgage Calculator
Calculate your monthly payment, total interest and the full amortization schedule for your mortgage. Free and no sign-up.
Pension Calculator
Calculate your estimated retirement pension in Spain: years contributed, regulatory base and percentage. Free and up to date.
IRPF Calculator 2026
Calculate your IRPF income tax on your annual income in Spain. 2026 brackets from 9.5% to 24.5% with deductions. Free and up to date.
Unemployment Calculator
Calculate your Spanish unemployment benefit (paro): months of entitlement and how much you will receive. 70% and 60% of your regulatory base. Free.
Who they are for
Our calculators are useful for shoppers who want to work out discounts, freelancers and businesses managing VAT, students solving proportions and anyone who wants to make a quick calculation without installing anything.
Problems they solve
Working out a percentage of an amount, finding the final price after a discount, adding or removing VAT to an invoice or solving a simple rule of three are the most common use cases these tools cover.
How they work
Enter the values in the fields, select the mode you need and the result appears instantly. All tools include a copy button so you can take the result anywhere.