Automotive Conversions

This page contains some JavaScript formulas to convert fuel efficiency, horsepower, torque, speed, weight, and temperature. Simply type the number in one box, press TAB, and the conversion will appear in the other boxes in that group.

Fuel Efficiency Conversions

MPG - miles per gallon (American)
DIN - liters per 100 km (European)
MPG - miles per gallon (British)

The formulas used are:
MPG (US) = 235.21458 / DIN
1 US gal = 3.7854118 liters
1 mile = 1.609344 km
MPG (UK) = 282.48093 / DIN
1 UK gal = 4.54609 liters
NOTE: European specs are usually based on the NEDC (new European driving cycle) which differs from USA test cycles like the FTP75 so that fuel economy numbers are not really directly comparable.

Power Conversions

SAE Horsepower (American)
kW kiloWatt
DIN Horsepower, PS (Pferdestärke)

The formulas used are:
SAE = kW * 1.3410
DIN = kW * 1.3596217
NOTE: Mercedes-Benz engine power is usually specified in kiloWatts, with 5 kW increments.

Torque Conversions

lb-ft (Foot Pounds, American)
Nm (Newtonmeter, European)

The formulas used are:
Nm = lb-ft * 1.355816
1 ft = 0.3048 m
1 lb = 0.453592 kg
1 kg = 9.80665 N

Speed Conversions

MPH - miles per hour (American)
km/h - kilometers per hour (Metric)
feet per second
m/s meters per second
Knots - naval and aeronautic speed

The formulas used are:

km/h = MPH * 1.609344
FPS = km/h * 0.91134
m/s = km/h * 0.27777778
Knots = MPH * 0.8684

Obey posted limits.

Weight Conversions

US Tons (American)
Metric Tons
Pounds (lb)
Kilograms

The formulas used are:
kg = lb * 0.453592
US tons = lb /2000
Metric tons = kg / 1000

Temperature Conversions

Celsius (Metric)
Fahrenheit (American)
Kelvin

The formulas used are:
Celsius = (Fahrenheit-32) * (5/9)
Kelvin = Celsius + 273.15

This page was copied and corrected from another page after I got tired of the numerous errors it had. The numbers should be more accurate now.