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12 calculators

General

Time math, color codes, weather comfort, fuel costs, and the other numbers daily life keeps asking for. Type a value and the answer is already there: free, private, and signup-free.

Calculators in this category
12
Tools
Cost
Free
Forever
Result type
Live
Results

General

All General calculators

Converters, timers, and everyday estimators. Every tool recalculates on each keystroke.

12 total
12

Vehicle Mileage Calculator

General

Find your real-world km per litre after a tank refill.

Mileage = Distance / Litres

Open

Aspect Ratio Calculator

General

Compute the missing width or height to maintain an aspect ratio.

Find missing W or H given ratio

Open

RGB ↔ HEX Color Converter

General

Convert between RGB triplet and HEX color code.

hex = #RRGGBB

Open

Unix Timestamp Converter

General

Convert between Unix timestamp (seconds since epoch) and human-readable date.

Date ↔ Unix seconds since 1970

Open

Hours Calculator

General

Work hours between a start time and end time, with break deduction and overnight handling.

Net = (End − Start) − Break

Open

Time Card Calculator

General

Weekly time-card with daily start, end and break — auto computes regular and overtime pay.

Weekly Pay = Reg×Rate + OT×Rate×1.5

Open

BTU Calculator

General

BTU/hr cooling capacity for an air conditioner sized to a room.

BTU = Area × 25 × sun × ceiling + kitchen + people

Open

Wind Chill Calculator

General

Feels-like temperature combining air temperature and wind speed.

WC = 13.12 + 0.6215T − 11.37V^0.16 + 0.3965T·V^0.16

Open

Heat Index Calculator

General

Apparent temperature combining heat and humidity.

HI = Rothfusz polynomial in T(°F), RH(%)

Open

Love Calculator

General

Fun compatibility test: combines two names and computes a percentage match using a classic playground algorithm.

Reduce digit-pair counts of LOVES letters in combined names → 1–99 %

Open

Dice Roller

General

Roll any dice (D4-D100) virtually. Increment Roll # to re-roll; live stats panel shows min, max, expected value.

Roll = Σ (1..sides) × N + modifier

Open

Bra Size Calculator

General

Recommended bra size from underbust and bust measurements, with sister sizes.

Band ≈ underbust + 4-5″ ; Cup = bust − band

Open

More to explore

Other calculator categories

Specialized tools across health, construction, school math, engineering, general, developer, cooking, and academic.

4

Health

Pet age, body fat, strength metrics

Browse tools
5

Construction

Area, materials, stairs, roof pitch

Browse tools
3

School Math

Fractions, percentages, geometry

Browse tools
3

Engineering

Circuits, beams, unit conversions

Browse tools
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Why use these calculators

Answers on every keystroke

Change an input and the output follows instantly. No submit button, no reload, no spinner.

Everyday formulas, shown in full

From heat index to time cards, each tool prints the formula it runs and defines every field.

Private by design

The math runs on your device. Your hours, mileage, and measurements are never uploaded.

Frequently asked questions

Everyday utilities that do not fit a single specialty: hours and time card math, color code converters, heat index and wind chill, BTU sizing, gas mileage, aspect ratios, dice rolls, and more.