Quick Math — Percentages, Fractions, GPA, Tips & More

Sometimes you need a quick calculation and don't want to pull out a calculator app or do the mental math. These three tools handle the everyday math that actually comes up in real life.

Percentage Calculator

The most common math problem? Figuring out tips and discounts. You're at a restaurant with friends, the bill comes to €85, and you want to leave 15%. Sure, you could multiply 85 by 0.15 in your head, but why bother? The percentage calculator does it instantly.

It also works the other direction — if you see a jacket marked 40% off for €54, you can quickly figure out what the original price was. Same tool, super useful when you're shopping and want to know if a discount is actually worth it. No login, no BS, just type in your numbers and get the answer.

Age Calculator

How old were you when that thing happened? You have a concert ticket from 2008 and you're trying to remember how old you were back then. Rather than doing the year math, just use the age calculator. Put in your birth date (March 15, 1992, let's say) and it tells you exactly how many years, months, and days you've been alive.

It's great for trivia too. Your friend mentions they were born in 1995, and you want to know if they're actually older or younger than they look. Or you're filling out a form that asks for your age on a specific date — this tool handles that calculation instantly.

Roman Numeral Converter

This one's for when you're reading something with Roman numerals and can't decode them mentally. You see "MCMXCIV" on a monument and want to know what year that actually is. The Roman numeral converter works both ways — convert Arabic numbers to Roman or Roman to Arabic.

It's surprisingly useful if you watch old movies with copyright dates like "MMXXIII," or if you're naming something fancy and want to use Roman numerals correctly. You're definitely not going to remember the rules for when to use subtraction notation (IV vs IIII) off the top of your head, so having a tool that gets it right every time is genuinely helpful.

All three tools work right in your browser — your data never leaves your device, and you don't need to create an account. Just load the page and calculate.

Fraction Calculator

Adding ⅓ + ¼ in your head? The fraction calculator handles addition, subtraction, multiplication, and division of fractions. Enter two fractions, pick an operation, and see the result automatically simplified. It also shows the step-by-step work — finding common denominators, performing the operation, and reducing — so it's great for checking homework or understanding the process.

GPA Calculator

End of semester and you need to know your GPA. The GPA calculator lets you add courses with their grade and credit hours, then calculates your weighted GPA instantly. Add as many courses as you need, and the total updates with each change. Works for both 4.0 and weighted scales.

Tip Calculator

The bill is $67.50 and you want to leave 18% split three ways. The tip calculator handles it. Enter the bill amount, select a tip percentage (or type a custom one), choose how many people are splitting, and see each person's share. It includes quick reference buttons for common tip percentages — 15%, 18%, 20%, 25% — so you can compare instantly.

Number to Words

You're writing a check (yes, people still do that) and need to write "$12,345.67" in words. Or you're generating invoice text programmatically and need numbers spelled out. The number to words converter converts any number — including decimals and negatives — into written English. It handles numbers from zero to the trillions and beyond.