Skip to main content

Convert Pounds per hour to Pounds per second

Instantly convert Pounds per hour (lb/hr) to Pounds per second (lb/s) with our free online calculator.

Reviewed by Christopher FloiedUpdated

Formula: lb/hr to lb/smultiply by 2.7778e-4

Reference Table

Pounds per hour (lb/hr)Pounds per second (lb/s)
10.000277778
50.00138889
100.00277778
250.00694446
500.0138889
1000.0277778

How to Convert Pounds per hour to Pounds per second

Formula

To convert Pounds per hour (lb/hr) to Pounds per second (lb/s): multiply by 2.7778e-4

Step-by-Step

  1. Start with your value in Pounds per hour (lb/hr).
  2. Multiply by 2.7778e-4 to perform the conversion.
  3. The result is your value expressed in Pounds per second (lb/s).

Conversion Factor

1 lb/hr = 0.000277778 lb/s

Reverse Factor

1 lb/s = 3599.99 lb/hr

Worked Example

Convert 25 Pounds per hour to Pounds per second: 25 lb/hr = 0.00694446 lb/s

About Pound per hour (lb/hr)

An imperial mass-flow unit (≈ 0.453592 kg/hr = 1.25998 × 10⁻⁴ kg/s). lb/hr is the universal working unit in US HVAC, steam engineering, petroleum refining, and chemical process plants. US boiler ratings are traditionally given in lb/hr of saturated steam output: a 'boiler horsepower' (BHP) is defined as 34.5 lb/hr of saturated steam at 212 °F per ASME PTC 4.1, so a '500 BHP boiler' produces 17,250 lb/hr. ASHRAE Handbook chapters on humidification, central plants, district heating, and refrigeration all use lb/hr. Refinery feed rates appear in lb/hr in older facility documentation (newer plants increasingly use kg/hr internationally and BPD for crude). Fuel consumption on large industrial engines, marine prime movers (with bunker fuel oil), and standby diesels is routinely quoted in lb/hr.

About Pound per second (lb/s)

An imperial mass-flow unit (≈ 0.453592 kg/s per NIST SP 811). lb/s is the dominant working unit in US aerospace engineering for turbomachinery: turbojet, turbofan, and turboprop engine performance data published by P&W, GE Aviation, Honeywell, and Rolls-Royce North America quote corrected and uncorrected mass flow in lb/s on type-certificate data sheets and FAR Part 33 power-plant certification documents per FAA Advisory Circular 33-2B. US-edition combustion textbooks (Glassman, Turns, Cengel & Boles) and gas-turbine engineering textbooks (Mattingly, Saravanamuttoo, Boyce) use lb/s throughout. Reference values: a GE F404 turbojet (F/A-18 Hornet) airflow ~146 lb/s at takeoff; GE9X (Boeing 777X) ~1,600 lb/s; CF6-80C2 (747-400) ~1,769 lb/s; F-1 first-stage rocket engine (Saturn V) ~5,683 lb/s of RP-1 + LOX; SpaceX Merlin 1D ~520 lb/s. Convert lb/s to kg/s by multiplying by 0.4536; to lb/hr by multiplying by 3,600; to lb/min by multiplying by 60.

Quick Facts

  • 1 Pound per hour equals 0.000277778 Pounds per second
  • 1 Pound per second equals 3599.99 Pounds per hour
  • Pound per hour is a unit of mass flow rate
  • Pound per second is a unit of mass flow rate
  • This conversion is commonly used in chemical processing, fuel systems, and environmental monitoring
  • The Pound per hour belongs to the imperial system

Common Pound per hour to Pound per second Conversions

Pounds per hour (lb/hr)Pounds per second (lb/s)
0.010.00000277778
0.10.0000277778
0.250.0000694446
0.50.000138889
10.000277778
20.000555557
30.000833335
50.00138889
100.00277778
150.00416667
200.00555557
250.00694446
500.0138889
750.0208334
1000.0277778
2500.0694446
5000.138889
10000.277778
50001.38889
100002.77778

Understanding Pounds per hour

The Pound per hour (symbol: lb/hr) is a unit of mass flow rate. An imperial mass-flow unit (≈ 0.453592 kg/hr = 1.25998 × 10⁻⁴ kg/s). lb/hr is the universal working unit in US HVAC, steam engineering, petroleum refining, and chemical process plants. US boiler ratings are traditionally given in lb/hr of saturated steam output: a 'boiler horsepower' (BHP) is defined as 34.5 lb/hr of saturated steam at 212 °F per ASME PTC 4.1, so a '500 BHP boiler' produces 17,250 lb/hr. ASHRAE Handbook chapters on humidification, central plants, district heating, and refrigeration all use lb/hr. Refinery feed rates appear in lb/hr in older facility documentation (newer plants increasingly use kg/hr internationally and BPD for crude). Fuel consumption on large industrial engines, marine prime movers (with bunker fuel oil), and standby diesels is routinely quoted in lb/hr.

It belongs to the imperial measurement system.

Pounds per hour are commonly used in chemical processing, fuel systems, and environmental monitoring.

Understanding Pounds per second

The Pound per second (symbol: lb/s) is a unit of mass flow rate. An imperial mass-flow unit (≈ 0.453592 kg/s per NIST SP 811). lb/s is the dominant working unit in US aerospace engineering for turbomachinery: turbojet, turbofan, and turboprop engine performance data published by P&W, GE Aviation, Honeywell, and Rolls-Royce North America quote corrected and uncorrected mass flow in lb/s on type-certificate data sheets and FAR Part 33 power-plant certification documents per FAA Advisory Circular 33-2B. US-edition combustion textbooks (Glassman, Turns, Cengel & Boles) and gas-turbine engineering textbooks (Mattingly, Saravanamuttoo, Boyce) use lb/s throughout. Reference values: a GE F404 turbojet (F/A-18 Hornet) airflow ~146 lb/s at takeoff; GE9X (Boeing 777X) ~1,600 lb/s; CF6-80C2 (747-400) ~1,769 lb/s; F-1 first-stage rocket engine (Saturn V) ~5,683 lb/s of RP-1 + LOX; SpaceX Merlin 1D ~520 lb/s. Convert lb/s to kg/s by multiplying by 0.4536; to lb/hr by multiplying by 3,600; to lb/min by multiplying by 60.

It belongs to the imperial measurement system.

Pounds per second are commonly used in chemical processing, fuel systems, and environmental monitoring.

Why Convert Pounds per hour to Pounds per second?

Converting between Pounds per hour and Pounds per second is a frequent requirement for engineers, scientists, and students working with mass flow rate values. Different industries and regions favour different unit systems, so having a dependable conversion tool saves time and prevents errors in technical calculations. Whether you are verifying a specification sheet, cross-checking simulation results, or preparing a report for an international audience, accurate mass flow rate conversion is essential.

Frequently Asked Questions

How do I convert Pounds per hour to Pounds per second?

An imperial mass-flow unit (≈ 0. To convert Pounds per hour to Pounds per second, multiply by 2.7778e-4. For example, 25 lb/hr equals 0.00694446 lb/s.

How many Pounds per second are in 1 Pound per hour?

There are 0.000277778 Pounds per second in 1 Pound per hour.

How many Pounds per hour are in 1 Pound per second?

There are 3599.99 Pounds per hour in 1 Pound per second.

What is the formula for Pound per hour to Pound per second conversion?

The formula is: multiply by 2.7778e-4. This means 1 lb/hr = 0.000277778 lb/s.

Is a Pound per hour bigger than a Pound per second?

Yes. One Pound per hour is larger than one Pound per second because 1 lb/hr equals 0.000277778 lb/s, which is less than 1.

When do you need to convert between Pounds per hour and Pounds per second?

An imperial mass-flow unit (≈ 0. Pound per hour and Pound per second are both mass flow units, so conversion comes up whenever one source of information uses one unit and another uses the other — a classic cross-reference challenge in engineering, trade, travel, and everyday life.

More Mass Flow Rate Conversions

Related Tools