Flow Rate Calculator

Flow Rate & Pressure Calculator

Convert between litres per minute (LPM), litres per hour (LPH) and gallons per minute (GPM), then compare pressure in BAR or PSI to get a quick view of overall cleaning power.

Flow Rate Converter

Litres per minute 21 LPM
Litres per hour 1,260 LPH
Gallons per minute 5.55 GPM
LPM → LPH = multiply by 60
LPH → LPM = divide by 60
GPM → LPM = multiply by 3.78541
LPM → GPM = divide by 3.78541
A machine rated at 21 LPM delivers 1,260 litres per hour and 5.55 gallons per minute.

Pressure & Cleaning Power

Pressure 200 BAR
Cleaning power score 4,200
Formula: LPM × BAR = quick cleaning power score for comparing machines.
Industrial / heavy-duty cleaning
21 LPM at 200 BAR gives a cleaning power score of 4,200.

Quick Comparison Table

Litres per minute Litres per hour Gallons per minute
10 LPM600 LPH2.64 GPM
12 LPM720 LPH3.17 GPM
15 LPM900 LPH3.96 GPM
18 LPM1,080 LPH4.76 GPM
20 LPM1,200 LPH5.28 GPM
21 LPM1,260 LPH5.55 GPM
24 LPM1,440 LPH6.34 GPM
25 LPM1,500 LPH6.60 GPM
30 LPM1,800 LPH7.93 GPM
36 LPM2,160 LPH9.51 GPM
Tip: some suppliers use LPH because the number looks bigger, while US specs often use GPM. Converting everything back to LPM and BAR makes machine comparisons much easier.
Guide:
Under 1,500 = light duty
1,500 to 2,500 = commercial duty
2,500 to 4,000 = heavy commercial
Over 4,000 = industrial / heavy-duty
Ideal for pressure washer buying guides, spec comparison pages and product support content.