Science & Engineering Converters
Convert pressure and energy units for engineering, physics, medicine and industry.
Need to know what 32 psi is in bar for tyre inflation, or how many joules are in a food Calorie? Science and engineering conversions span everyday tasks like checking tyre pressure and industrial applications like specifying boiler ratings in kPa or BTU. Pressure units include pascal, bar, psi, atmosphere and mmHg - the last being the clinical standard for blood pressure. Energy units cover joules, kilocalories, kilowatt-hours and BTU, bridging nutrition labels, electricity bills and heating system ratings.
Frequently asked questions
32 psi equals approximately 2.21 bar. Typical car tyre pressures range from 30-36 psi (2.07-2.48 bar). European pressure gauges usually show bar while US gauges use psi, so this is one of the most practical pressure conversions.
1 joule equals approximately 0.239 calories (small calories). For food energy, 1 food Calorie (kcal) equals 4184 joules. A 2000 kcal daily diet contains about 8,368,000 joules or 8.37 MJ.
Normal blood pressure of 120/80 mmHg equals approximately 16 kPa systolic and 10.7 kPa diastolic. Blood pressure is always measured in mmHg clinically, but kPa conversion is sometimes needed in scientific contexts.
To convert kilowatt-hours to BTU, multiply by 3412.14. So 1 kWh = 3412 BTU. A gas boiler rated at 100,000 BTU/hour produces about 29.3 kW of heat. This conversion is common when comparing UK heating systems (kW) with US ratings (BTU).
1 standard atmosphere (atm) equals 1.01325 bar or 14.696 psi. This is the average air pressure at sea level and is used as a baseline in chemistry, physics and diving safety calculations.
Need other converters? Explore our metric converters, digital storage and time and date.