ENVIS Centre, Ministry of Environment & Forest, Govt. of India
Printed Date: Friday, August 9, 2024
Common Units of Fire Variables
Common Units of Fire Variables
Character

Commonly used C.G.S. unit

Metric unit

Abbreviation

Conversion factor C.G.S. to metric system

Flame height

feet

meter

M

0.3048

Flame angle

degree F

degree C

^{0}C

5/9 (F32)

Fuel quantity

pounds/sq.ft

Kilogram/sq.metre

Kg/m^{2}

4.882

Temperature

degree.Fahrenheit

degree Celsius
degree Kelvin

^{0}C
^{0}K

^{0}C=5/9 (^{0}F32)
^{0}K=^{0}C+273.2

Wind speed

Feet/second
miles/hour

meter/second
kilometer/hour

m/s
km/hr

0.3048
1.6093

Rate of forward spread

feet/second
feet/hour
mile/hour

metre/second
metre/hour
kilometer/hour

m/s
m/hr
km/hr

6.3048
20.12
1.6093

Rate of area spread

sq.ft/second
acre/hour

sq.metre/second
hectare/hour

m^{2}/s
ha/hr

0.0929
0.4047

Heat quantity

British Thermal
Unit Calorie

Joule

J

4.186

Heat yield and
Heat of combustion

Btu/pound
Calorie/gram

Kilojoule/kilogram
Kilojoule/kilogram

KJ/kg
KJ/kg

2.326
4.186

Heat capacity

Btu/pound^{0}F

Kilojoule/kilogram^{0}C

KJ/kg^{0}C

4.0248

Heat flow

Btu/second

Watt

W

1054.8

Fire intensity

Btu/second/ft.

Kilowatt/metre

KW/m

3.461

Source: Luna, R.K. 2007. Principles and practices of forest fire control.