Everyday Calculators
The tools you reach for daily: age, dates, tips, discounts, unit conversions, random generators and quick household math.
Age Calculator
Calculate exact age in years, months, days — plus weeks, hours, minutes and next birthday.
CalculateArea Calculator
Area of a rectangle, triangle, circle or trapezoid with substituted formulas and steps.
CalculateBasic Calculator
Four-function calculator with power and modulo — add, subtract, multiply, divide, ^, mod.
CalculateBig Number Calculator
Add, subtract, multiply, divide and exponentiate very large numbers, with E-notation support.
CalculateBra Size Calculator
Find your bra size from band and bust measurements in US, UK or EU sizing systems.
CalculateBtu Calculator
Estimate the air-conditioner BTU/h you need for any room based on size, sun and insulation.
CalculateCircle Calculator
From a radius get the diameter, circumference and area of a circle with worked steps.
CalculateCommon Factor Calculator
Find all factors, common factors, GCD and LCM of two integers with Euclid steps.
CalculateConcrete Calculator
Estimate concrete volume, 80 lb and 60 lb bag counts and weight for slabs, columns and footings.
CalculateConversion Calculator
Convert length, weight, temperature, volume, speed and area between all common units.
CalculateDate Calculator
Days between two dates, or add/subtract years, months, weeks and days — with business-day mode.
CalculateDay Counter
Days between two dates — total, business days and a weeks-and-days breakdown.
CalculateDay of the Week Calculator
What day of the week is any date? Plus week number, day of year and fun facts.
CalculateDensity Calculator
Compute density from mass and volume in kg/m³, g/cm³ or lb/ft³, with substance comparisons.
CalculateDew Point Calculator
Dew point from air temperature and humidity via the Magnus formula, with comfort zones.
CalculateDice Roller
Roll virtual dice — d4 through d100 — with a modifier, then see totals, averages and every roll.
CalculateDistance Calculator
Euclidean distance between two 2-D points, plus midpoint and slope, with full working.
CalculateElectricity Calculator
Estimate appliance electricity usage and cost per day, month and year from watts and hours.
CalculateEngine Horsepower Calculator
Estimate engine horsepower from quarter-mile weight, elapsed time and trap speed (Fox method).
CalculateExponent Calculator
Raise any base to any power — integer, negative or fractional — with a growth chart.
CalculateFactor Calculator
All divisors, factor pairs and prime factorization of a number, plus classification.
CalculateGolf Handicap Calculator
Turn your recent scores into a World Handicap System index using differentials and the best-N method.
CalculateGravel Calculator
Estimate gravel tonnage, cubic yards, 50 lb bags and cost for any area and depth.
CalculateGreatest Common Factor Calculator
GCF of two numbers via Euclid’s algorithm, plus factor lists, LCM and coprimality.
CalculateHalf-life Calculator
Solve exponential decay: remaining quantity after any time for a given half-life.
CalculateHeat Index Calculator
Find how hot it really feels — temperature plus humidity with NWS danger-zone classification.
CalculateHeight Calculator
Convert height between cm and feet/inches, and predict a child’s adult height from parents.
CalculateHorsepower Calculator
Convert torque and RPM to horsepower, with kW, PS and watt conversions and full steps.
CalculateHours Calculator
Find hours and minutes between a start and end time, minus breaks — with optional pay.
CalculateLeast Common Multiple Calculator
LCM of two integers via GCF, with a multiples table that shows where they first meet.
CalculateLog Calculator
Logarithms in any base — 10, e, 2 or custom — with change-of-base working.
CalculateLove Calculator
Just for fun: a deterministic name-based compatibility score from 0% to 100%.
CalculateMass Calculator
Convert mass between kilograms, grams, pounds, ounces, stone and metric tons.
CalculateMatrix Calculator
2×2 matrix analysis: determinant, inverse, trace, transpose and real eigenvalues.
CalculateMolarity Calculator
Molarity from mass, molecular weight and volume — with moles and a dilution guide.
CalculateMolecular Weight Calculator
Molar mass from any chemical formula — with per-element breakdown, percentages and a mass donut.
CalculateMulch Calculator
Estimate mulch volume in cubic yards and bags needed, with cost, for any bed size.
CalculateOhms Law Calculator
Enter any two of voltage, current and resistance to solve the third — plus power in watts.
CalculatePercent Off Calculator
Work out the final price after a percent-off discount, including stackable additional discounts.
CalculatePercentage Calculator
Three modes: X% of Y, X is what % of Y, and percentage change between two values.
CalculatePrime Factorization Calculator
Break any integer into its prime factors with division steps and divisor counts.
CalculatePythagorean Theorem Calculator
Solve a² + b² = c² for the missing side, plus angles, area and perimeter.
CalculateQuadratic Formula Calculator
Solve ax² + bx + c = 0 with the quadratic formula — real, repeated or complex roots.
CalculateRandom Number Generator
Generate random integers in any range, with or without duplicates.
CalculateRatio Calculator
Simplify a:b to lowest terms and solve proportions like a:b = c:x for the missing value.
CalculateResistor Calculator
Decode a 4-band resistor color code into resistance, tolerance and min/max range.
CalculateRight Triangle Calculator
Solve right triangles: sides, acute angles, area, perimeter and altitude.
CalculateRoofing Calculator
Roof area from footprint and pitch, plus squares, shingle bundles and 10% waste.
CalculateRoot Calculator
Any nth root of any number — square, cube or higher — with even-root-of-negative guard.
CalculateScientific Calculator
Full scientific keypad — sin, cos, tan, logs, roots, powers, memory and Deg/Rad, with instant exact results.
CalculateSleep Calculator
Find the best bedtime for your wake-up time using 90-minute sleep cycles.
CalculateSlope Calculator
Find slope, angle of incline, distance and y = mx + b from two points, step by step.
CalculateSquare Footage Calculator
Square footage for rectangles, circles and triangles — with material cost and waste allowance.
CalculateStair Calculator
Step count, riser height, total run and stringer length for any floor-to-floor rise.
CalculateSurface Area Calculator
Surface area of cubes, spheres, cylinders, cones and rectangular prisms.
CalculateTile Calculator
Tiles needed for an area — grout gap, 10% waste, boxes and cost included.
CalculateTime Calculator
Add or subtract two times in days/hours/minutes/seconds, plus a weekly time card with overtime.
CalculateTime Card Calculator
Weekly time card: daily hours, overtime over 40 and gross pay with 1.5× OT.
CalculateTime Duration Calculator
Time between two date-times — hours, minutes, decimal hours — with overnight support.
CalculateTip Calculator
Calculate tip and total for any bill, split between any number of people, with round-up option.
CalculateTriangle Calculator
Solve any triangle: area, perimeter and angles from base & height or three sides (Heron).
CalculateVoltage Drop Calculator
Voltage drop for copper wire runs — single or three phase — with AWG comparison and NEC verdicts.
CalculateVolume Calculator
Volume of a cube, box, cylinder, sphere or cone with step-by-step substituted formulas.
CalculateWeight Calculator
Convert between kilograms, pounds and stones instantly, both directions, with reference tables.
CalculateWind Chill Calculator
Feels-like temperature in cold wind — NWS formula, frostbite times and danger zones.
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