LCM Calculator
Finds the least common multiple of two or more whole numbers — the smallest number that every one of them divides into evenly.
LCM of 12 and 18: 12 = 22 × 3 and 18 = 2 × 32. Take the highest power of each prime: 22 × 32 = 36.
GCF / HCF Calculator
Finds the greatest common factor (also called the highest common factor) of two or more whole numbers — the largest number that divides them all.
GCF of 48 and 180: 48 = 24 × 3 and 180 = 22 × 32 × 5. Take the lowest power of each shared prime: 22 × 3 = 12.
Ratio Calculator
Simplifies a ratio to its lowest terms and lists equivalent ratios — handy for recipes, maps, scale drawings and mixing.
Simplify 20 : 30. Both numbers divide by 10, so 20 : 30 = 2 : 3. Equivalent ratios include 4 : 6, 6 : 9 and 10 : 15.
Fraction Calculator
Adds, subtracts, multiplies and divides fractions, then simplifies the answer and shows it as a fraction, a mixed number and a decimal.
3/4 + 1/6: use a common denominator of 12 → 9/12 + 2/12 = 11/12 ≈ 0.9167.
Prime Number Checker
Tells you whether a whole number is prime or composite, and breaks composite numbers down into their prime factors.
97 is prime — nothing divides it except 1 and itself. But 91 is not prime: 91 = 7 × 13.
Square Root Calculator
Finds the square root of any non-negative number, simplifies the radical where possible, and flags perfect squares.
√144 = 12, because 12 × 12 = 144. Not every root is whole: √50 = 5√2 ≈ 7.0711, and 50 is not a perfect square.
Exponent Calculator
Raises a base number to any power — including negative bases and negative exponents, which flip the answer into a fraction.
210 means 2 multiplied by itself 10 times: 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 = 1,024.
Mean, Median & Mode Calculator
Paste a list of numbers to get the mean (average), the median (middle value) and the mode (most frequent value), plus the range.
For 4, 8, 8, 10, 15: the sum is 45, so the mean is 45 ÷ 5 = 9; the middle value (median) is 8; and 8 appears twice, so the mode is 8.
Rounding Calculator
Rounds a number to a set number of decimal places, or to the nearest ten, hundred, thousand or ten thousand.
Round 3.14159 to 2 decimal places. The third decimal is 1, which is less than 5, so we round down: 3.14.
Long Division Calculator
Divides whole numbers the long way and shows every step — the quotient, the remainder, and how each digit is worked out.
987 ÷ 12: 12 goes into 98 eight times (8 × 12 = 96, remainder 2). Bring down the 7 to make 27; 12 goes in twice (2 × 12 = 24, remainder 3). Answer: 82 remainder 3.
No calculator matches that search — try “fraction”, “average” or “root”.
How it works
Pick a calculator
Use the search box or the quick links at the top to jump straight to the tool you need — LCM for schedules and common denominators, long division for step-by-step working, and so on.
Type your numbers
Every answer updates the moment you type. Lists can be separated by commas or spaces, and each calculator explains any input it cannot use instead of failing quietly.
Check the working, then copy
Each result comes with the reasoning behind it — prime factors, common denominators, division steps — and a Copy button so you can paste the answer straight into your homework or lesson plan.
Why MathKit shows its working
A bare answer helps you finish a worksheet, but it does not help you learn. Teachers mark the method, not just the final number — so MathKit pairs every answer with the steps a teacher would write on the board: the prime factor trees behind an LCM, the common denominator behind a fraction sum, and every bring-down step of a long division. Check your own working against ours, spot where the two part ways, and the next problem gets easier. Everything runs entirely in your browser: no sign-up, no uploads, and nothing you type ever leaves your device.
Frequently asked questions
Are these calculators really free?
Yes — all ten calculators are free to use as often as you like, with no account, no downloads and no limits. MathKit is part of a small network of free tool sites (listed in the footer) that keep everyday calculators and guides free for everyone.
What is the difference between GCF and HCF?
Nothing at all. GCF (greatest common factor) is the term most US textbooks use; HCF (highest common factor) is common in the UK and elsewhere. Both mean the largest whole number that divides each of your numbers exactly, which is why the calculator carries both names.
Why does the square root of 50 say “not a perfect square”?
A perfect square is a whole number multiplied by itself, like 144 = 12 × 12. 50 sits between 49 (7²) and 64 (8²), so its square root cannot be a whole number. The calculator simplifies it instead: √50 = 5√2 ≈ 7.0711.
Can the Mean, Median & Mode calculator handle a long list?
Yes. Paste the whole list — test scores, prices, measurements — separated by commas or spaces. It sorts the values for you, so you do not need to put them in order first, and it also reports the count, sum, smallest, largest and range.
Do you store the numbers I type?
No. Every calculation happens in your own browser using plain JavaScript. Nothing is sent to a server, saved, or shared — close the tab and the numbers are gone.
What does a negative exponent do?
A negative exponent flips the power into a fraction: 2−3 = 1 / 23 = 1/8 = 0.125. Try it in the Exponent Calculator — it shows both the fraction and the decimal so the idea clicks.
About MathKit
MathKit is a small, focused set of the math calculators students and teachers reach for most: common multiples and factors, ratios, fractions, primes, roots, powers, averages, rounding and long division. It is built for US classrooms and homework desks — plain English, big readable numbers, exact answers, and the working shown every time. Questions or a calculator you would like to see added? Write to us at [email protected].