Math calculators available on CalcWarehouse.com
Percentage Calculator
Solve everyday percentage problems such as increase, decrease, and what percent of.
Percentage Increase Calculator
Calculate the percentage increase from an original value to a new value. Growth rate, price increase.
Percentage Decrease Calculator
Calculate the percentage decrease from an original value to a new value. Discount, decline.
Percentage Change Calculator
Calculate the percentage change between two values. Positive or negative change.
Weighted Average Calculator
Calculate weighted average from values and weights. GPA, grades, portfolio returns.
Leap Year Calculator
Check if a year is a leap year. Leap year rules: divisible by 4, except centuries, unless divisible by 400.
Permutation Calculator
Calculate permutations P(n,r) – number of ways to arrange r items from n. Order matters.
Combination Calculator
Calculate combinations C(n,r) – number of ways to choose r items from n. Order does not matter.
Age Calculator
Find exact age in years, months, and days. Age calculator with hour, minute, second. Age on specific future date. Days until next birthday.
Date Difference Calculator
Find the exact time between two dates in years, months, days, total days and weeks.
Time Calculator
Add or subtract hours, minutes and seconds. Convert to total hours, minutes and seconds.
Ratio Calculator
Simplify ratios and compare proportional relationships between quantities.
Discount Calculator
Compute discount amounts, sale prices, and savings percentages for shopping and pricing.
Standard Deviation Calculator
Compute standard deviation, variance, mean. Population or sample.
Fraction Calculator
Simplify fractions and convert them to decimal and percentage form.
GPA Calculator
Calculate weighted GPA from course grades and credits. 4.0 scale.
Unit Converter
Convert length, mass, temperature, volume, area, time, speed. cm to inches, kg to lbs.
Grade Calculator
Convert score to percentage and letter grade. Enter points earned and total points.
Final Grade Calculator
Find what score you need on the final exam to reach your target grade. Enter current grade, weights and target.
Weighted GPA Calculator
Calculate weighted GPA with letter grades and optional weight for honors/AP courses. Credits and grade points.
SAT Score Calculator
Calculate total SAT score from EBRW and Math section scores. Each section 200–800, total 400–1600.
CGPA Calculator
Calculate CGPA on a 10-point scale. Enter grade points and credits per course. Common in Indian universities.
Age Difference Calculator
Find the exact age difference between two people. Enter both dates of birth for years, months, days and total days.
Time Card Calculator
Calculate work hours with break deduction and overtime pay. Clock in/out, break minutes, hourly rate.
Proportion Calculator
Solve proportions a/b = c/d. Find the unknown value in proportional relationships.
Mean Median Mode Calculator
Compute mean, median, mode, min and max from a list of numbers. Statistics helper.
Probability Calculator
Calculate probability from favorable and total outcomes. Simple probability formula.
Z Score Calculator
Compute z-score from value, mean and standard deviation. Standard normal distribution.
Variance Calculator
Calculate variance, standard deviation and mean. Population or sample variance.
Random Number Generator
Generate random integers between a minimum and maximum. Fair random picker.
Binary Calculator
Add and subtract binary numbers. Binary arithmetic for computer science.
Hex Calculator
Add hexadecimal numbers. Hex arithmetic for programming and color codes.
Roman Numeral Calculator
Convert numbers to Roman numerals and Roman numerals to numbers. 1–3999.
Age in Months Calculator
Calculate age in months from birth date to a reference date. Baby and child age.
Time Until Date Calculator
Find days, hours, minutes and seconds until a future date from today.
Business Days Calculator
Count business days (weekdays) between two dates. Excludes weekends.
Work Hours Calculator
Calculate total work hours from multiple start and end time sessions.
Countdown Calculator
Count down days, hours, minutes and seconds until a target date or event.
Length Converter
Convert between meters, centimeters, inches, feet, yards, miles and kilometers.
Weight Converter
Convert between kilograms, grams, pounds and ounces.
Temperature Converter
Convert between Celsius, Fahrenheit and Kelvin.
Volume Converter
Convert between liters, milliliters, gallons, cups and fluid ounces.
Area Calculator
Calculate area of rectangle, circle and triangle from dimensions.
Volume Calculator
Calculate volume of cube, cylinder and sphere from dimensions.
Concrete Calculator
Estimate concrete volume and bags needed for slabs and footings.
Brick Calculator
Estimate bricks needed for a wall from dimensions and brick size.
Paint Calculator
Estimate gallons of paint needed for walls from dimensions and coverage.
Tile Calculator
Estimate tiles needed for a floor from floor and tile dimensions.
Roofing Calculator
Estimate shingle bundles needed for roof area with pitch factor.
Stair Calculator
Calculate riser height and tread depth from total rise and run.
Cement Calculator
Estimate cement bags needed for concrete volume and mix ratio.
Steel Weight Calculator
Calculate weight of rebar and steel plates from dimensions.
LCM Calculator
Find least common multiple of two integers for fractions and number theory problems.
GCD Calculator
Find greatest common divisor of two integers for simplification and divisibility checks.
Exponent Calculator
Compute powers from base and exponent for algebra, science and growth calculations.
Square Root Calculator
Find principal square roots of non-negative numbers for algebra and geometry.
Quadratic Formula Calculator
Solve ax² + bx + c = 0. Find real or complex roots using the quadratic formula.
Random Password Generator
Create secure random passwords with length and character options. No sign-up.
Scientific Notation Calculator
Convert numbers to and from scientific notation. Decimal and scientific form (e.g. 1.5e3).
Log Calculator
Calculate log base b of x. Logarithm with any base. Formula: log_b(x) = ln(x) / ln(b).
Trigonometry Calculator
Calculate sin, cos, tan for any angle. Degrees or radians. Trigonometry helper.
Matrix Calculator
Add, subtract, or multiply 2x2 matrices. Matrix arithmetic for algebra and linear algebra.
Time Zone Converter
Convert time between UTC offsets. Enter time and source/target offsets in hours.
Date to Day Calculator
Find day of week from any date. Enter year, month, day to get Sunday, Monday, etc.
AI Token Calculator
Estimate token count for LLM prompts and AI API usage with character or word-based heuristics.
Math Calculators – Percentages, Ratios, Age and Discounts
Everyday math questions often fall into a few familiar patterns: what percentage is this score, how old is someone in years and months, what is the simplest form of this ratio and how much will I pay after a sale discount. CalcWarehouse.com collects these questions into a focused set of math calculators that you can access instantly from any device. Instead of performing repeated calculations by hand or switching between generic spreadsheets, you can rely on calculators optimized for each scenario.
The percentage calculator supports three common tasks: finding what percentage one number is of another, computing the value after a percentage increase or decrease and reversing the process to find the original amount before a percentage change. By clearly labeling each mode and showing the underlying formula, the calculator helps students and professionals avoid confusion around where to divide and when to multiply by 100. It is particularly useful for interpreting test scores, survey results, tax amounts and business KPIs.
The age calculator turns birth dates into exact ages expressed in years, months and days, which can be surprisingly tricky to compute manually because of varying month lengths and leap years. By relying on JavaScript's native date handling and an explicit breakdown of the steps, the tool lets you copy accurate ages into forms, contracts or HR systems. It is also a helpful teaching aid when explaining how calendars and date arithmetic work.
Ratio and discount calculators round out the collection by addressing shopping and comparison scenarios. A ratio calculator simplifies numbers to their smallest form so that you can quickly see equivalent comparisons, such as map scales or recipe adjustments. A discount calculator shows the discount amount, final price and implied savings percentage for sale items, allowing you to check whether promotional claims line up with the actual math before you buy.