Simple Calculators. Instant Answers.
Calculators that show their work.
Twenty-two carefully built calculators for pay, loans, percentages, dates, health, home and math. Every answer is computed in your browser with the formula printed right next to it.
Popular calculators
The tools people reach for most often.
Percentage Calculator
Percentages, increases, discounts and margins in six modes.
Open calculatorPaycheck Calculator
Turn an hourly rate or salary into weekly, monthly and annual pay.
Open calculatorLoan Payment Calculator
Monthly payment, total interest and a full amortization schedule.
Open calculatorAge Calculator
Exact age in years, months, days — plus your next birthday.
Open calculatorDate Calculator
Add or subtract dates, count days between, or count business days.
Open calculatorTip Calculator
Split a bill and tip fairly in a couple of taps.
Open calculatorProfit Calculator
Net profit, margin, ROI and break-even for real product costs.
Open calculatorBMI Calculator
Body mass index and weight category from height and weight.
Open calculatorCompound Interest Calculator
Future value of savings or investments with recurring contributions.
Open calculatorBrowse by category
Money
Everyday personal finance math: pay, loans, rent, savings and tips.
Business
Pricing, margin, markup, profit and freelance tools for sellers.
Dates & Time
Age, date arithmetic and business-day counting.
Health & Fitness
Body metrics, calorie estimates, hydration and wellness math.
Home & Property
Paint, area, compound interest and household project calculators.
Math & Conversion
Unit conversion, GPA and general arithmetic helpers.
Why use CalculateWise
Instant, in-browser math
No page reloads and no server round-trips. Change an input and the result card updates immediately.
Verified formulas
Every calculator uses the standard published formula and is checked against known reference values.
Private by design
Nothing you type leaves your device. We never store dates of birth, salaries or loan details.
Explained, not just answered
Each page shows the formula, a worked example and the common uses, so you can check the result yourself.
Latest guides
How to Calculate a Percentage of Any Number
The one formula behind every percentage question, with worked examples you can check in seconds.
3 min readHow to Calculate Percentage Increase and Decrease
Compare an old value to a new value correctly — and avoid the classic mistake of dividing by the wrong number.
3 min readHow to Calculate a Discount and Final Sale Price
Work out what you actually pay and what you actually save at any percent off.
2 min readHow to Calculate Hourly Pay With Overtime
Turn a rate, regular hours and overtime hours into weekly, monthly and annual gross pay.
4 min readHow to Convert a Salary to Hourly Pay
The standard divisors for monthly, biweekly, weekly, daily and hourly equivalents.
3 min readHow to Calculate a Loan Payment
The amortization formula behind every fixed monthly payment, explained plainly.
5 min read