37+ Every calculator you keep reaching for a search engine to find

Find a percentage of a number, work out what percent one number is of another, or measure a percentage change.

A full expression calculator — arithmetic, powers, roots and trig — for the math a percentage or a fraction tool can't cover.

Paste your grades and credit hours and get your GPA back instantly, on the standard 4.0 scale.

Work out the score you need on what's left to hit the grade you're aiming for.

Paste a list of numbers and get the mean, median, mode, range and standard deviation at once.

Add, subtract, multiply or divide two fractions and get the answer already simplified.

Enter a, b and c and get both roots of ax² + bx + c = 0.

Estimate a monthly payment including taxes, insurance, PMI and HOA — not just principal and interest — with the full amortization schedule behind it.

Turn a principal, interest rate and term into a payment, with total interest and the full amortization schedule behind it.

See how a balance grows over time at a given rate and compounding frequency, with optional regular contributions and principal vs. interest broken out separately.

Monthly car payment and total cost — accounting for a trade-in, sales tax and fees, with the full amortization schedule behind it.

Convert between hourly, weekly, biweekly, monthly and annual gross pay.

Project the future value of an investment from an initial amount, regular contributions and an expected annual return.

Your Equated Monthly Installment from a loan amount, rate and term, with the principal vs. interest split.

Turn a cost and a final value into a gain or loss and a return-on-investment percentage.

See what today's money will be worth in the future, or what a future amount is worth today, at a given inflation rate.

Work out the contribution a target amount and a deadline actually require, with the growth from interest broken out separately.

Project your retirement savings from your current age, current balance, regular contributions and an optional employer match.

Interest and total amount from a principal, rate and time period — simple interest, never compounding.

Height and weight, metric or imperial, in for a body mass index, its category, and the healthy weight range behind it.

Your Basal Metabolic Rate — calories burned at complete rest — using the Mifflin-St Jeor equation.

Your estimated daily calorie needs — BMR scaled by your activity level.

An estimated due date, gestational age and trimester from the first day of your last period.

An estimated ovulation day, fertile window and next period date from the first day of your last period.

Estimate body fat percentage from a few tape measurements, U.S. Navy method.

Enter a birth date and get an exact age in years, months and days.

The exact number of days, weeks and months between any two dates.

How many days are left until a date you pick, updated the moment you change it.

Find the elapsed time between two clock times, including overnight spans.

Count the weekday working days between two dates, weekends excluded.

Add or subtract days, weeks, months or years from a date, with calendar-exact results.

The tip and the per-person split, from a bill total and a party size.

A sale price and the amount saved, from an original price and a percent off.

Profit, profit margin and markup from a cost and a selling price — two clearly separate percentages.

The tax and the total, from a price and the rate you enter.

Convert between currencies using an exchange rate you supply — clearly labeled, never presented as live.

Estimate a trip's fuel cost from distance, fuel economy and price per gallon or litre.