Flow Rate Converter
Common Flow Rate Conversions
| From | To | Multiply by |
|---|---|---|
| 1 US GPM | L/min | 3.78541 |
| 1 US GPM | L/s | 0.0630902 |
| 1 US GPM | m³/h | 0.227124 |
| 1 Imp GPM | L/min | 4.54609 |
| 1 m³/h | L/min | 16.6667 |
| 1 m³/h | L/s | 0.277778 |
Pressure Converter
Common Pressure Conversions
| From | To | Multiply by |
|---|---|---|
| 1 PSI | Bar | 0.0689476 |
| 1 PSI | kPa | 6.89476 |
| 1 Bar | PSI | 14.5038 |
| 1 Bar | kPa | 100 |
| 1 atm | kPa | 101.325 |
| 1 atm | mmHg | 760 |
| 1 atm | inHg | 29.9213 |
| 1 atm | mH₂O | 10.3323 |
Energy / Power Converter
Common Energy / Power Conversions
| From | To | Multiply by |
|---|---|---|
| 1 kW | BTU/h | 3,412.14 |
| 1 kW | kcal/h | 859.845 |
| 1 kW | HP | 1.34102 |
| 1 TR | kW | 3.51685 |
| 1 TR | BTU/h | 12,000 |
| 1 HP | kW | 0.7457 |
Temperature Converter
Temperature Formulas
| Conversion | Formula |
|---|---|
| °C to °F | °F = °C × 9/5 + 32 |
| °F to °C | °C = (°F − 32) × 5/9 |
| °C to K | K = °C + 273.15 |
| °F to °R | °R = °F + 459.67 |
Length / Distance Converter
Common Length Conversions
| From | To | Multiply by |
|---|---|---|
| 1 inch | mm | 25.4 |
| 1 foot | mm | 304.8 |
| 1 yard | m | 0.9144 |
| 1 m | feet | 3.28084 |
| 1 m | inches | 39.3701 |
Pipe Sizing Quick Reference
Look up nominal pipe sizes across DN (metric), NPS (imperial), and actual outside diameter. Type a value to filter.
| DN (Metric) | NPS (Imperial) | Actual OD (mm) | Actual OD (inches) |
|---|---|---|---|
| DN15 | 1/2" | 21.3 | 0.840" |
| DN20 | 3/4" | 26.7 | 1.050" |
| DN25 | 1" | 33.4 | 1.315" |
| DN32 | 1 1/4" | 42.2 | 1.660" |
| DN40 | 1 1/2" | 48.3 | 1.900" |
| DN50 | 2" | 60.3 | 2.375" |
| DN65 | 2 1/2" | 73.0 | 2.875" |
| DN80 | 3" | 88.9 | 3.500" |
| DN100 | 4" | 114.3 | 4.500" |
| DN125 | 5" | 141.3 | 5.563" |
| DN150 | 6" | 168.3 | 6.625" |
| DN200 | 8" | 219.1 | 8.625" |
| DN250 | 10" | 273.0 | 10.750" |
| DN300 | 12" | 323.8 | 12.750" |
Frequently Asked Questions
How do I convert GPM to litres per second?
To convert US gallons per minute (GPM) to litres per second (L/s), multiply the GPM value by 0.0630902. For example, 10 US GPM equals 0.631 L/s. Imperial GPM is slightly larger: multiply by 0.0757682 to get L/s. Use the Flow Rate tab above for instant results.
What is the difference between PSI and Bar?
PSI (pounds per square inch) is the imperial unit of pressure, while Bar is the metric unit. 1 Bar equals 14.5038 PSI. In HVAC and refrigeration, system pressures are commonly stated in PSI in North America and in Bar or kPa in Europe and Asia.
How many BTU per hour is 1 kW?
1 kilowatt (kW) equals 3,412.14 BTU per hour. This conversion is essential for sizing heat pumps and air conditioning systems, where capacity may be rated in BTU/h (common in the US) or kW (common internationally).
What is a Ton of Refrigeration (TR)?
A Ton of Refrigeration (TR) is a unit of cooling capacity equal to 12,000 BTU/h or 3.51685 kW. It originates from the cooling power of melting one short ton (2,000 lb) of ice in 24 hours. Commercial chillers and large air conditioning systems are commonly rated in TR.
How do DN pipe sizes relate to NPS and actual outside diameter?
DN (Diametre Nominal) is the metric designation and NPS (Nominal Pipe Size) is the imperial equivalent. Neither equals the actual pipe outside diameter (OD). For example, DN25 corresponds to NPS 1 inch, but the actual OD is 33.4 mm. Use the Pipe Sizing tab above for a full reference table covering DN15 through DN300.
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