SumHexa — Calculate anything.

Unit converter

Convert length, area, volume, mass, temperature, speed, time, pressure, energy, power and frequency.

Changing modes clears your inputs and result.

Lengths must be zero or positive. Inches, feet, yards and miles use international definitions.

Swaps the units, keeps your entered value and recalculates the result immediately.

Both dots and commas are accepted as decimal separators.

Your inputs stay in your browser. Displayed results are rounded to a maximum of 12 significant digits.

Method and assumptions

Method version 1.3.0 · Updated

Length

Formula: y = x × f(from) ÷ f(to)

Lengths must be zero or positive. Inches, feet, yards and miles use international definitions.

value
Value to convert
from
From unit
to
To unit
Mass

Formula: y = x × f(from) ÷ f(to)

Masses must be zero or positive. Pounds and ounces are avoirdupois units, not troy units.

value
Value to convert
from
From unit
to
To unit
Temperature

Formula: °F = °C × 9/5 + 32 ; °C = (°F − 32) × 5/9 ; K = °C + 273.15

Negative temperatures are accepted in Celsius and Fahrenheit, down to absolute zero.

value
Value to convert
from
From unit
to
To unit
Area

Formula: y = x × f(from) ÷ f(to)

Areas must be zero or positive. Square feet, inches and yards use international definitions. Example: 1 ha = 10,000 m².

value
Value to convert
from
From unit
to
To unit
Volume

Formula: y = x × f(from) ÷ f(to)

Volumes must be zero or positive. US liquid gallons and fluid ounces differ from imperial units; dry gallons are excluded. Example: 1 US liquid gallon = 3.785411784 L.

value
Value to convert
from
From unit
to
To unit
Speed

Formula: y = x × f(from) ÷ f(to)

Non-negative values: speed magnitude only, without direction. A knot is one international nautical mile per hour. Example: 36 km/h = 10 m/s.

value
Value to convert
from
From unit
to
To unit
Time

Formula: y = x × f(from) ÷ f(to)

Non-negative fixed durations: 1 day = 24 h and 1 week = 7 days. No calendar arithmetic, months, years or daylight-saving changes. Example: 1.5 h = 90 min.

value
Value to convert
from
From unit
to
To unit
Pressure

Formula: y = x × f(from) ÷ f(to)

Non-negative pressures. Unit conversion only: keep the same reference, absolute or gauge. Atmospheric pressure is not added. Example: 1 bar = 100 kPa.

value
Value to convert
from
From unit
to
To unit
Energy

Formula: y = x × f(from) ÷ f(to)

Non-negative energy, without power or cost calculations. Calories use the thermochemical definition: 1 cal = 4.184 J. Example: 1 kWh = 3,600,000 J.

value
Value to convert
from
From unit
to
To unit
Power

Formula: y = x × f(from) ÷ f(to)

Non-negative power. Horsepower (hp) means international mechanical horsepower here: 1 hp ≈ 745.6998716 W. No energy use or cost is estimated.

value
Value to convert
from
From unit
to
To unit
Frequency

Formula: y = x × f(from) ÷ f(to)

Non-negative frequencies. Revolutions per minute are treated as cycles per minute (60 rpm = 1 Hz), without additional mechanical interpretation.

value
Value to convert
from
From unit
to
To unit

Deterministic floating-point calculation. The displayed result is rounded to a maximum of 12 significant digits.

Sources: NIST — SI conversion factors.

Calculate with code

These short examples use the same inputs and core calculation as this tool. Adapt validation and formatting to your application.

JavaScript
const meters = 5 * 0.3048; // 1.524 m from 5 international feet