Conversion Table

Pressure Unit Conversion Table

 

	atm	ata ( kg/cm2 )	Torr ( mm Hg)	in Hg (32℉)	mm water (4℃)	in water (60℉)	bar	Mpa	Kpa	PSI ( lb/in)
atm	1	1.033	760	29.92	10332.56	406.79	1.013	0.1013	101.32	14.69
ata ( kg/cm2 )	0.968	1	735.56	28.96	10000.03	393.71	0.981	0.0981	98.07	14.22
Torr ( mm Hg)	1.316x10-3	1.36 x10-3	1	0.03937	13.60	0.535	1.333x10-3	1.333x10-4	0.1333	0.0194
in Hg (32℉)	0.03342	0.0345	25.4	1	345.40	13.60	0.03386	3.387x10-3	3.387	0.491
mm water (4℃)	9.67x10-5	9.99x10-5	0.0736	2.895x10-3	1	2.904x10-3	9.81x10-5	9.81x10-6	9.81x10-3	1.422x10-3
in water (60℉)	2.456x10-3	2.54x10-3	1.866	0.0736	25.4	1	2.49x10-3	2.49x10-4	0.249	0.03613
bar	0.9872	1.02	750.06	29.53	10197.44	401.47	1	0.1	100	14.50
Mpa	9.872	10.20	7500	295.3	101974.42	4018.60	10	1	1000	145
Kpa	9.87x10-3	0.01	7.50	0.2953	101.97	4.018	0.01	0.001	1	0.145
PSI ( lb/in)	0.068	0.070	51.71	2.036	703.09	27.71	0.0689	6.893x10-3	6.893	1

Unit	Bar	Mbar	Pa	KPa	MPa (Torr)*	Kgf/cm2	mm hg	mmWC	PSI	1"WC
1bar	1	1000	100.000	100	0,1	1,01972	750,062	10197,16	14,5038	401,463
1mbar	0,001	1	100	0,1	0,0001	1,01972.10-3	0,7501	10,1972	0,0145	401,463.10-3
1 Pa	0,0001	0,01	1	0,001	0,000001	1,01972.10-5	0,0075	0,10197	0,000145	4,01463.10-3
1 KPa	0,01	10	1000	1	0,001	0,010197	7,5006	101,972	0,145	4,01463
1 MPa	10	10,000	1,000.00	1000	1	10,1972	7500,62	101972	145,038	4014,63
1kgf/C2	0,981	980,7	980,666	98.0665	0,09807	1	735,56	10,000	14,2233	393,7008
1mm Hg	0,00133	1,333	133,63	0,13332	0,1333.10-3	0,001359	1	13,5951	0,01934	0,53524
MMWC	0,000098	0,098	9,807	0,009807	9,807106	0,001	0,07356	1	0,0012	39,37008.10.3
1 pSI	0,06895	68,95	6895,06	6,895	6,895.10-3	0,07031	51,717	703,01	1	27,68
1’’WC	2,490893,10-3	2,49089	249,089	0,249089	0,249089.10-3	2,54.10-3	1,86832	25,4	0,03613	1

 

1Pa=1 N/m2

1Kpa=1Kn/m2

1Mpa=1Mn/m

 Conversion factors for commonly used pressure units

 *1 Torr was originally the same as 1 mmHg. However, redefinitions of the two units have made them slightly different by a margin too small to show in this table

Conversion Table
of commonly used pressure units

 

SI Units - Engineering units (based on the metre)

 

to from		SI units bar           mbar		µbar	Pa	kPa	MPa	Engineering units mmHg     mmWS     mWS			kp/mm2	kp/cm2	atm
SI units	1 bar	1	103	106	105	100	0.1	750.064	10.1972 ∙ 103	10.1972	10.1972 ∙ 10-3	1.01972	0.986923
	1 mbar	10-3	1	103	100	0.1	0.1 ∙ 10-3	750.064 ∙ 10-3	10.1972	10.1972 ∙ 10-3	10.1972 ∙ 10-6	1.01972 ∙ 10-3	0.986923 ∙ 10-3
	1 µbar	10-6	10-3	1	0.1	0.1 ∙ 10-3	0.1 ∙ 10-6	750.064 ∙ 10-6	10.1972 ∙ 10-3	10.1972 ∙ 10-6	10.1972 ∙ 10-9	1.01972 ∙ 10-6	0.986923 ∙ 10-6
	1 Pa	10-5	0.01	10	1	10-3	10-6	7.50064 ∙ 10-3	101.972 ∙ 10-3	101.972 ∙ 10-6	101.972 ∙ 10-9	10.1972 ∙ 10-6	9.86923 ∙ 10-6
	1 kPa	0.01	10	10 ∙ 103	103	1	10-3	7.50064	101.972	101.972 ∙ 10-3	101.972 ∙ 10-6	10.1972 ∙ 10-3	0.986923 ∙ 10-3
	1 MPa	10	10 ∙ 103	10 ∙ 106	106	103	1	7.50064 ∙ 103	101.972 ∙ 103	101.972	101.972 ∙ 10-3	10.1972	9.86923
Engineering units	1 mmHg	1.33322 ∙ 10-3	1.33322	1.33322 ∙ 103	133.322	133.322 ∙ 10-3	133.322 ∙ 10-6	1	13.5951	13.5951 ∙ 10-3	13.5951 ∙ 10-6	1.35951 ∙ 10-3	1.31579 ∙ 10-3
	1 mmWS	98.0665 ∙ 10-6	98.0665 ∙ 10-3	98.0665	9.80665	9.80665 ∙ 10-3	9.80665 ∙ 10-6	73.5561 ∙ 10-3	1	10-3	10-6	0.1 ∙ 10-3	96.7841 ∙ 10-6
	1 mWS	98.0665 ∙ 10-3	98.0665	98.0665 ∙ 103	9.80665 ∙ 103	9.80665	9.80665 ∙ 10-3	73.5561	103	1	10-3	0.1	96.7841 ∙ 10-3
	1 kp/mm2	98.0665	98.0665 ∙ 103	98.0665 ∙ 106	9.80665 ∙ 106	9.80665 ∙ 103	9.80665	73.5561 ∙ 103	106	103	1	100	96.7841
	1 kp/cm2	0.980665	0.980665 ∙ 103	0.980665 ∙ 106	98.0665 ∙ 103	98.0665	98.0665 ∙ 10-3	735.561	10 ∙ 103	10	0,01	1	0.967841
	1 atm	1.01325	1.01325 ∙ 103	1.01325 ∙ 106	101.325 ∙ 103	101.325	101.325 ∙ 10-3	760	10.3323 ∙ 103	10.3323	10.3323 ∙ 10-3	1.03323	1

 

Corresponding pressure units:

 1 Pa      = 1 N/m²

n 1 hPa      = 1 mbar

n 1 mmHg  = 1 Torr

n 1 kp/cm² = 1 at (atü)

 

Notes

The table refers to DIN 1301 Part 1 (2002) and Part 3 (1979).

In accordance with the Execution Ordinance to the law on units in metrology (Ferderal German Units Ordinance) from 13th December 1985 only the following units are admissible for pressures:

n   pascal (Pa)

n   bar (bar)

n   millimetre of mercury (mmHg), but only for blood pressure and the pressure of other physical liquids in medicine

 

Valid for these units in accordance with Federal German Unit Ordinance are the definitions and conversion factors per DIN 1301.

 

Listed in Part 1 of this standard

n   pascal as derived SI unit with special name and with special unit symbol

n   bar as generally applicable unit outside the SI

n   millimetre of mercury as unit outside the SI with limited area of application Part 3 of this standard defines amongst other things conversion factors for the following units

n   conventional millimetre of mercury (mmHg)

n   conventional metre of water (mWS)

n   torr (Torr)

n   technical atmosphere (at)

n   standard atmosphere (atm)

SI units - Engineering units (based on the foot)

 

to from		SI units bar             mbar		µbar	Pa	kPa	MPa	Engineering units psi                 ft H2O         in. H2O			in. Hg
SI units	1 bar	1	103	106	105	100	0.1	14.50377	33.4553	401.463	29.52998
	1 mbar	10-3	1	103	100	0.1	0.1	14.50377	33.4553	401.463	29.52998
							∙ 10-3	∙ 10-3	∙ 10-3	∙ 10-3	∙ 10-3
	1 µbar	10-6	10-3	1	0.1	0.1	0.1	14.50377	33.4553	401.463	29.52998
						∙ 10-3	∙ 10-6	∙ 10-6	∙ 10-6	∙ 10-6	∙ 10-6
	1 Pa	10-5	0.01	10	1	10-3	10-6	0.1450377	0.334553	4.01463	0.2952998
								∙ 10-3	∙ 10-3	∙ 10-3	∙ 10-3
	1 kPa	0.01             10		10 ∙ 103	103	1	10-3	0.1450377	0.334553	4.01463	0.2952998
	1 MPa	10	10	10	106	103	1	0.1450377	0.334553	4.01463	0.2952998
			∙ 103	∙ 106				∙ 103	∙ 103	∙ 103	∙ 103
	1 psi	68.94757	68.94757	68.94757	6.894757	6.894757	6.894757	1	2.30666	27.6799	2.036020
ts		∙ 10-3		∙ 103	∙ 103		∙ 10-3
ring uni	1 ft H2O	29.8907 ∙ 10-3	29.8907	29.8907 ∙ 103	2.98907 ∙ 103	2.98907	2.98907 ∙ 10-3	433.5275 ∙ 10-3	1	12	0.8826709
nginee	1 in. H2O	2.49089 ∙ 10-3	2.49089	2.49089 ∙ 103	0.249089 ∙ 103	0.249089	0.249089 ∙ 10-3	36.12729 ∙ 10-3	83.3333 ∙ 10-3	1	73.55591 ∙ 10-3
E	1 in. Hg	33.86389	33.86389	33.86389	3.386389	3.386389	3.386389	0.4911542	1.132925	13.59510	1
		∙ 10-3		∙ 103	∙ 103		∙ 10-3

 

Corresponding pressure units:

 1 Pa       = 1 N/m²

n 1 psi       = 1 lbf/in.²

Notes

The table refers to ISO 31-1:1992 and ISO 31-3:1992

For lengths ISO 31-1 defines conversion factors for units no longer to be used:

n 1 mmHg   = 1 Torr

n 1 kgf/cm²  = 1 at

n inch (in)

n foot (ft)

For pressures ISO 31-3 defines conversion factors for units no longer to be used:

n pound-force per square inch (lbf/in.²)

n conventional millimetre of water (mmH2O)

n conventional millimetre of mercury (mmHg)

n Torr (Torr)

n technical atmosphere (at)

n standard atmosphere (atm)

Pressure units
v t e	Pascal	Bar	Technical atmosphere	Standard atmosphere	Torr	Pound per square inch
	(Pa)	(bar)	(at)	(atm)	(Torr)	(lbf/in2)
1 Pa	1 Pa ≡ 1 Pa	1 Pa = 10−5 bar	1 Pa = 1.0197×10−5 at	1 Pa = 9.8692×10−6 atm	1 Pa = 7.5006×10−3 Torr	1 Pa = 0.000 145 037 737 730 lbf/in2
1 bar	105	≡ 100 kPa ≡ 106 dyn/cm2	= 1.0197	= 0.98692	= 750.06	= 14.503 773 773 022
1 at	98066.5	0.980665	≡ 1 kgf/cm2	0.967 841 105 354 1	735.559 240 1	14.223 343 307 120 3
1 atm	≡ 101325	≡ 1.01325	1.0332	1	760	14.695 948 775 514 2
1 Torr	133.322 368 421	0.001 333 224	0.001 359 51	1/760 ≈ 0.001 315 789	1 Torr ≈ 1 mmHg	0.019 336 775
1 lbf/in2	6894.757 293 168	0.068 947 573	0.070 306 958	0.068 045 964	51.714 932 572	≡ 1 lbf/in2