Free online calculators for everyday decisions
Precise calculators with step-by-step explanations that make complex numbers easy to understand.
Money & finance
Health & fitness
- BMI calculator
- TDEE Calculator: Daily Calories & Maintenance
- Calorie calculator
- BMI calculator for children
Investing & retirement
Featured calculators
Selected tools for everyday decisions.
How much house can I afford
Enter your annual income, monthly debts, down payment, interest rate, and term. The calculator uses the 28/36 affordability rule to estimate the home price, the maximum monthly payment, and the loan it supports.
Open calculatorCompound interest calculator
Compound interest is interest earned on both your starting amount and interest already added. Choose an annual rate, a term, and a compounding frequency to estimate how a balance may grow.
Open calculatorCalorie calculator
Enter body details for ages 19–78, select activity and a goal, then follow the visible chain from estimated resting energy through activity factor and estimated maintenance to the fixed goal adjustment.
Open calculatorPercentage calculator
Need help with a percentage? Choose one of three common questions, enter two numbers, and get an answer straight away. The labels tell you whether each number is the percentage, part, whole, old value, or new value.
Open calculatorLatest from the blog
Guides and analysis behind the numbers.
Buy Now, Pay Later vs Credit Card: Which Costs Less This Black Friday?
Pay-in-4 looks free at checkout. A credit card looks expensive. The cheaper option this Black Friday depends on whether you clear the balance — and on late fees, APR, and rewards.
Tipping before or after sales tax: what the difference actually is
Same bill, same tax rate, same percentage — only the base changes. The gap turns out to be one number you can work out in your head, and it is smaller than the argument suggests.
What does home charging cost compared with public charging?
The same electric car can cost twice as much per 100 km depending on where the energy comes from. Here is how to price your own mix, charging loss included.
When does a more efficient appliance actually pay for itself?
A new fridge or dryer saves electricity every year but costs money once. Here is how to work out which side wins, using the kWh figures already printed on the energy label.
More than just results
WiseCalcs goes a step further and explains the why behind every result, so you can make informed decisions with confidence.
- Step-by-step guides to complex financial concepts.
- Science-based health calculations.
- Transparent mathematical models.