28 free calculators · more every month

Every calculation, checked twice.

A free calculator hub for the numbers that run your day: doses and deadlifts, rent and roof pitches, grades and game stats. Type, tap, and get an answer you can trust, worked out step by step.

Instant results No sign-up, ever Formula shown on every page
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Percent is smart: 200 + 10% = 220.

28Calculators
7Categories
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FOUR GOOD PLACES TO START

Peptide Calculator

Any vial, any dose: mg, ml and syringe units.

mg

NDA Age Calculator

Eligibility checked against the exam window.

yr

UPSC Age Calculator

Age limits and attempts, by category.

IAS

Life Path Calculator

Your number from your birth date.

7
01

Fitness & Body

Training numbers and body measurements, without the guesswork.

5 TOOLS

Peptide Calculator

Reconstitute any vial: mg, ml and syringe units worked out for you.

mg ÷ ml

Bench Press Calculator

Estimate your one-rep max from any set, two formulas side by side.

w × (1 + r/30)

Strength Calculator

See how your lifts stack up against standards for your body weight.

1RM ÷ BW

Walking Calorie Calculator

Calories burned walking, by distance, pace and body weight.

MET × kg × h

Army Body Fat Calculator

The official tape-test body fat estimate used by the US Army.

neck + waist
02

Age, Date & Exams

Exact ages, working days and exam eligibility, down to the day.

4 TOOLS

Age Calculator Between Two Dates

Exact years, months and days between any two dates.

date₂ − date₁

Business Day Calculator

Add or count working days, skipping weekends automatically.

Mon – Fri only

NDA Age Calculator

Check your date of birth against the NDA exam eligibility window.

DOB ≤ cutoff

UPSC Age Calculator

Age limits and attempts for the civil services exam, by category.

age + attempts
03

Math & Statistics

Triangles and data sets, solved with the steps shown.

4 TOOLS

Right Triangle Calculator

Solve any right triangle: sides, angles, area and perimeter.

a² + b² = c²

Hypotenuse Calculator

Find the hypotenuse in one tap, with the working shown.

c = √a² + b²

Mean Calculator

The average of any list of numbers, with sum and count.

Σx ÷ n

Median Calculator

Median, mode and range for your data set, sorted for you.

middle x
04

Construction & Home

Materials and measurements for the job site and the house.

4 TOOLS

Cubic Yard Calculator

How much concrete, mulch or gravel your project really needs.

ft³ ÷ 27

Board Feet Calculator

Lumber volume and cost from board dimensions, in seconds.

T × W × L ÷ 144

Square Feet Calculator

Flooring, paint and room areas in square feet, fast.

L × W

Bitumen Calculator

Bitumen quantity for road and asphalt work, by mix percent.

% × mix (t)
05

Money & Life

Rent, support, savings goals and the real cost of things.

6 TOOLS

Discount Calculator

Sale price, savings and tax after any percent off.

P × (1 − d)

Coast FIRE Calculator

The number where work becomes optional: coast to retirement.

spend × 25

Child Support Calculator

Estimate support from income and custody, state by state.

% of income

Dental Implants Cost Calculator

What implants really cost, by tooth, type and extras.

$ × teeth

Prorated Rent Calculator

Fair rent for a partial month, moving in or moving out.

rent ÷ days × d

CPM Calculator

Cost per thousand impressions for any ad campaign.

cost ÷ imp × 1K
06

Education

Grades and exam scores, predicted before the results arrive.

2 TOOLS

High School GPA Calculator

Weighted and unweighted GPA from your grades and credits.

Σ(g × cr) ÷ Σcr

APUSH Score Calculator

Turn practice-test sections into a predicted AP score, 1 to 5.

MCQ + SAQ + DBQ
07

Games & Fun

The lighter side of numbers: games, charts and a little numerology.

3 TOOLS

Pokemon Type Calculator

Every type matchup: what hits hard and what barely scratches.

×2 · ½ · ×0

Blooket Calculator

Tokens and XP from Blooket game modes, worked out for you.

tokens ÷ min

Life Path Calculator

Your life path number from your birth date, and what it means.

Σ digits → 1–9
01

Checked twice

Every formula on this site is tested against hand-worked examples before the page goes live. If the math is wrong, the page does not ship.

02

Fast by design

No apps, no accounts, no heavy pages. CalcCheck is built to open instantly on any phone, even on a slow connection.

03

Steps, not just answers

Each calculator shows its formula and a worked example, so you can see exactly where your number came from.

Quick questions

CalcCheck is a free online calculator hub. It brings 28 calculators for fitness, money, math, construction, dates, education and games into one fast site, with no sign-up and no downloads. Every calculator shows its formula and a worked example, and each one is tested before it goes live. New calculators are added regularly.
Yes. Every calculator on CalcCheck is free to use, with no sign-up, no account and no download. Open a page, type your numbers, get your answer.
Each calculator is built from the standard formula for its job and tested against hand-worked examples before it is published. Every page shows the formula it uses, so you can verify the method yourself. For medical, legal or tax decisions, treat the result as an estimate and confirm with a professional.
The way you expect from real life: after a plus or minus, percent means a share of the number before it, so 200 + 10% = 220 and 85 − 15% = 72.25. On its own, 50% simply becomes 0.5.
No. Calculations run in your own browser. There are no accounts and nothing you type into a calculator is sent to a server or saved.