Everyday Calculators
Popular percentage, age, BMI, loan, discount, tax and date calculators.
Percentage Calculator
Calculate a percentage, percentage change, or what percent one number is of another.
Open tool →CalculatorsAge Calculator
Calculate age in years, months, and days from a date of birth.
Open tool →CalculatorsBMI Calculator
Calculate body mass index from height and weight with standard adult BMI ranges.
Open tool →CalculatorsLoan Calculator
Estimate a fixed monthly loan payment from principal, annual interest rate, and term.
Open tool →CalculatorsCompound Interest Calculator
Estimate future value from principal, interest rate, compounding frequency, and time.
Open tool →CalculatorsDiscount Calculator
Calculate sale price, discount amount, and savings percentage.
Open tool →CalculatorsTip Calculator
Calculate tip, total bill, and per-person amount for a group.
Open tool →CalculatorsSales Tax / VAT Calculator
Add or remove sales tax or VAT from a price using any tax rate.
Open tool →CalculatorsDate Difference Calculator
Find the number of days, weeks, months, and years between two dates.
Open tool →CalculatorsGrade Calculator
Calculate a weighted or simple grade percentage from earned and possible points.
Open tool →Why this category exists
Costovia groups related utilities so visitors can move from one task to the next without starting another search. Every tool has a dedicated URL and links back to this hub.
Explore Calculators
Use free calculators for age, BMI, percentages, loans, discounts, dates, grades and other everyday calculations on Costovia.
Choose a calculator for your question
Start with the quantity you need to calculate: percentages for ratios, dates for age, or height and weight for BMI. Check input units and the assumptions shown on the result before relying on an estimate.