A conversion factor is a multiplier that transforms one unit into another:
- Linear: target = source \u00d7 factor
- Non-linear: temperature uses addition too
- Factors are ratios: 1 m = 3.28084 ft \u2192 factor = 3.28084
7 SI base units:
- Meter (m) \u2014 length
- Kilogram (kg) \u2014 mass
- Second (s) \u2014 time
- Ampere (A) \u2014 electric current
- Kelvin (K) \u2014 temperature
- Mole (mol) \u2014 amount
- Candela (cd) \u2014 luminous intensity
- Identify source and target units
- Find the conversion factor between them
- Multiply (or apply the formula for temperature)
- Check: does the result make sense?
- For chain conversions, multiply factors together
Umrechnungsformeln
Mathematische Formeln und Gleichungen hinter Einheitenumrechnungen mit Rechenbeispielen.
Temperature Umrechnungsformeln
CalculatorCelsius to Fahrenheit
F = C × 9/5 + 32
Example: 25°C = 25 × 9/5 + 32 = 77°F
Fahrenheit to Celsius
C = (F - 32) × 5/9
Example: 77°F = (77 - 32) × 5/9 = 25°C
Celsius to Kelvin
K = C + 273.15
Example: 25°C = 25 + 273.15 = 298.15 K
Kelvin to Celsius
C = K - 273.15
Example: 300 K = 300 - 273.15 = 26.85°C
Fahrenheit to Kelvin
K = (F - 32) × 5/9 + 273.15
Example: 212°F = (212 - 32) × 5/9 + 273.15 = 373.15 K
Length Umrechnungsformeln
CalculatorMeters to Feet
ft = m × 3.28084
Example: 10 m = 10 × 3.28084 = 32.81 ft
Feet to Meters
m = ft × 0.3048
Example: 100 ft = 100 × 0.3048 = 30.48 m
Miles to Kilometers
km = mi × 1.60934
Example: 5 mi = 5 × 1.60934 = 8.05 km
Inches to Centimeters
cm = in × 2.54
Example: 12 in = 12 × 2.54 = 30.48 cm
Weight & Mass Umrechnungsformeln
CalculatorKilograms to Pounds
lb = kg × 2.20462
Example: 70 kg = 70 × 2.20462 = 154.32 lb
Pounds to Kilograms
kg = lb × 0.45359
Example: 150 lb = 150 × 0.45359 = 68.04 kg
Ounces to Grams
g = oz × 28.3495
Example: 8 oz = 8 × 28.3495 = 226.80 g
Volume Umrechnungsformeln
CalculatorLiters to US Gallons
gal = L × 0.264172
Example: 10 L = 10 × 0.264172 = 2.64 gal
US Cups to Milliliters
mL = cups × 236.588
Example: 2 cups = 2 × 236.588 = 473.18 mL
US Fluid Ounces to Milliliters
mL = fl oz × 29.5735
Example: 8 fl oz = 8 × 29.5735 = 236.59 mL
Speed Umrechnungsformeln
Calculatormph to km/h
km/h = mph × 1.60934
Example: 60 mph = 60 × 1.60934 = 96.56 km/h
km/h to m/s
m/s = km/h × 0.27778
Example: 100 km/h = 100 × 0.27778 = 27.78 m/s
Knots to km/h
km/h = knots × 1.852
Example: 30 knots = 30 × 1.852 = 55.56 km/h
Pressure Umrechnungsformeln
CalculatorPascal to Bar
bar = Pa × 0.00001
Example: 101325 Pa = 101325 × 0.00001 = 1.013 bar
PSI to Pascal
Pa = PSI × 6894.76
Example: 14.7 PSI = 14.7 × 6894.76 = 101325 Pa
ATM to Pascal
Pa = atm × 101325
Example: 1 atm = 1 × 101325 = 101325 Pa
Energy Umrechnungsformeln
CalculatorJoules to Calories
cal = J × 0.239006
Example: 1000 J = 1000 × 0.239006 = 239.01 cal
kWh to Joules
J = kWh × 3,600,000
Example: 1 kWh = 1 × 3,600,000 = 3,600,000 J
BTU to Joules
J = BTU × 1055.06
Example: 100 BTU = 100 × 1055.06 = 105,506 J
Power Umrechnungsformeln
CalculatorWatts to Horsepower
hp = W × 0.001341
Example: 746 W = 746 × 0.001341 = 1.0 hp
Horsepower to Watts
W = hp × 745.7
Example: 2 hp = 2 × 745.7 = 1491.4 W
kW to Horsepower
hp = kW × 1.341
Example: 100 kW = 100 × 1.341 = 134.1 hp
The Mathematics Behind Conversion
Linear Conversions
Most unit conversions are linear \u2014 you simply multiply by a conversion factor. For example, to convert meters to feet, multiply by 3.28084. The general formula is: target = source \u00d7 (toFactor / fromFactor)
Non-Linear Conversions
Temperature is the main exception. Because Celsius, Fahrenheit, and Kelvin have different zero points, conversion requires both multiplication and addition. For example: \u00b0F = \u00b0C \u00d7 9/5 + 32
Dimensional Analysis
For complex conversions, use dimensional analysis: write each conversion as a fraction where the units cancel. For example, converting miles per hour to meters per second: mph \u00d7 (1609.34 m/mi) \u00d7 (1 hr/3600 s) = m/s
All Category Formulas
Visit each category page for complete formula references and interactive calculators.
Formeln-FAQ
Common questions about conversion formulas and equations.