Clo - Clothing and Thermal Insulation

Clo is used as a measure of clothes thermal insulation.

The insulation effect of clothes can be measured in the unit "I_cl, Clo" - where

1 Clo = 0.155 m²K/W

Clo = 0 - corresponds to a naked person
Clo = 1 - corresponds to the insulating value of clothing needed to maintain a person in comfort sitting at rest in a room at 21 ℃ (70 ℉) with air movement of 0.1 m/s and humidity less than 50% - typically a person wearing a business suit

Clo - Clothing and Thermal Insulation
Clothing		Insulation
Clothing		I_cl, Clo	m²K/W
Nude		0	0
Underwear - pants	Pantyhose	0.02	0.003
	Panties	0.03	0.005
	Briefs	0.04	0.006
	Pants 1/2 long legs made of wool	0.06	0.009
	Pants long legs	0.1	0.016
Underwear - shirts	Bra	0.01	0.002
	Shirt sleeveless	0.06	0.009
	T-shirt	0.09	0.014
	Shirt with long sleeves	0.12	0.019
	Half-slip in nylon	0.14	0.022
Shirts	Tube top	0.06	0.009
	Short sleeve	0.09	0.029
	Light blouse with long sleeves	0.15	0.023
	Light shirt with long sleeves	0.20	0.031
	Normal with long sleeves	0.25	0.039
	Flannel shirt with long sleeves	0.30	0.047
	Long sleeves with turtleneck blouse	0.34	0.053
Trousers	Shorts	0.06	0.009
	Walking shorts	0.11	0.017
	Light trousers	0.20	0.031
	Normal trousers	0.25	0.039
	Flannel trousers	0.28	0.043
	Overalls	0.28	0.043
Coveralls	Daily wear, belted	0.49	0.076
Coveralls	Work	0.50	0.078
Highly-insulating coveralls	Multi-component with filling	1.03	0.160
Highly-insulating coveralls	Fiber-pelt	1.13	0.175
Sweaters	Sleeveless vest	0.12	0.019
	Thin sweater	0.20	0.031
	Long thin sleeves with turtleneck	0.26	0.040
	Thick sweater	0.35	0.054
	Long thick sleeves with turtleneck	0.37	0.057
Jacket	Vest	0.13	0.020
	Light summer jacket	0.25	0.039
	Smock	0.30	0.047
	Jacket	0.35	0.054
Coats and over-jackets and over-trousers	Overalls multi-component	0.52	0.081
	Down jacket	0.55	0.085
	Coat	0.60	0.093
	Parka	0.70	0.109
Sundries	Socks	0.02	0.003
	Thin soled shoes	0.02	0.003
	Quilted fleece slippers	0.03	0.005
	Thick soled shoes	0.04	0.006
	Thick ankle socks	0.05	0.008
	Boots	0.05	0.008
	Thick long socks	0.10	0.016
Skirts, dresses	Light skirt 15 cm. above knee	0.01	0.016
	Light skirt 15 cm. below knee	0.18	0.028
	Heavy skirt knee-length	0.25	0.039
	Light dress sleeveless	0.25	0.039
	Winter dress long sleeves	0.40	0.062
Sleepwear	Under shorts	0.10	0.016
	Short gown thin strap	0.15	0.023
	Long gown long sleeve	0.30	0.047
	Hospital gown	0.31	0.048
	long pajamas with long sleeve	0.50	0.078
	Body sleep with feet	0.72	0.112
Robes	Long sleeve, wrap, short	0.41	0.064
Robes	Long sleeve, wrap, long	0.53	0.082

An overall insulation - or Clo - value can be calculated by simply taking the Clo value for each individual garment worn by a person and adding them together. The mean surface area of the human body is approximately 1.8 m².