Mass Flow Converter
ScienceConvert mass flow rate between kilograms per second, kilograms per hour, pounds per hour, and grams per second — used for process and fluid engineering.
From
To
All conversionsfor 1 Kilograms per Hour (kg/hr)
| Kilograms per Second (kg/s) | 0.000277778 |
| Kilograms per Minute (kg/min) | 0.016666647 |
| Kilograms per Hour (kg/hr) | 1 |
| Grams per Second (g/s) | 0.277778 |
| Metric Tons per Hour (t/hr) | 0.001 |
| Pounds per Second (lb/s) | 0.00061239616 |
| Pounds per Hour (lb/hr) | 2.2046223 |
What is a Mass Flow?
The Mass Flow Converter converts mass flow rate between kilograms per second, kilograms per minute, kilograms per hour, grams per second, metric tons per hour, and the imperial pounds per second and pounds per hour. Mass flow rate measures how much mass of a substance moves past a point per unit time — a fundamental quantity in process engineering, particularly for gases and compressible flows where volumetric flow can vary with conditions.
Enter a value in any supported unit and the converter calculates the equivalent instantly. For the related molar quantity, see the Molar Flow Converter, and for volumetric flow, see the Flow Converter.
How to use this Mass Flow calculator
- Choose your starting unit from the source dropdown — for example, "Kilograms per Hour (kg/hr)".
- Enter the numeric value you want to convert in the input field.
- Choose your target unit from the destination dropdown — for example, "Kilograms per Second (kg/s)".
- Read the converted result, which updates instantly as you type or change units.
- Use the swap (⇅) button if you need to reverse the conversion direction.
- Use the copy button to grab the result for a process design calculation or mass balance report.
Formula & Methodology
The converter's base unit is kilograms per second (kg/s). Every supported unit has a fixed multiplier: - 1 kilogram per minute (kg/min) = 0.016667 kg/s - 1 kilogram per hour (kg/hr) = 0.000278 kg/s - 1 gram per second (g/s) = 0.001 kg/s - 1 metric ton per hour (t/hr) = 0.277778 kg/s - 1 pound per second (lb/s) = 0.453592 kg/s - 1 pound per hour (lb/hr) = 0.000126 kg/s Any conversion follows: Result = Input × (toBase of source unit ÷ toBase of target unit) Worked example — converting 500 kg/hr to kg/s: Result = 500 × (0.000278 ÷ 1) = 0.139 kg/s This is the value you'd use directly in an SI-unit process engineering calculation.
Frequently Asked Questions
Mass flow rate measures how much mass of a substance passes a given point per unit time, expressed in units like kilograms per second — distinct from volumetric flow rate, which measures volume per unit time and doesn't account for the substance's density.
Divide the kg/hr value by 3,600, since there are 3,600 seconds in an hour. Enter your value with 'Kilograms per Hour (kg/hr)' as the source and 'Kilograms per Second (kg/s)' as the target to apply this automatically.
Mass flow rate stays constant even as a fluid's density changes with temperature or pressure (relevant for gases and compressible flows), while volumetric flow rate can vary under the same conditions — this makes mass flow rate the more fundamental and reliable quantity for many process engineering calculations, particularly involving gases.
Multiply or divide by the fluid's density — mass flow rate equals volumetric flow rate multiplied by density. Use the [Flow Converter](/flow-converter/) for volumetric flow units and the [Density Converter](/density-converter/) for density conversions to work through this relationship.
This varies enormously by application — a small laboratory process might involve grams per second, while a large industrial plant might handle hundreds of tons per hour, so there's no single typical value; context determines the appropriate scale.
Molar flow rate measures the flow of moles of a substance rather than mass, and the two are related by the substance's molar mass (mass flow = molar flow × molar mass) — see the [Molar Flow Converter](/molar-flow-converter/) for that related quantity, common in chemical engineering.
Metric tons per hour keeps large industrial mass flow numbers in a manageable range — expressing a plant's material throughput in kg/s would produce awkwardly small numbers for genuinely large flows, so t/hr is the conventional unit for bulk material handling and large process streams.
Common measurement methods include Coriolis flow meters (which directly measure mass flow by detecting fluid-induced vibration changes), or indirect calculation from volumetric flow meter readings combined with a known or measured fluid density.
Chemical processing, oil and gas, power generation, food and beverage manufacturing, and pharmaceutical production all rely on accurate mass flow measurement and conversion for process control, material balance calculations, and regulatory reporting.
Yes — mass flow rate conversion works identically regardless of the substance's phase, since it's purely a mass-per-time relationship; this is actually one advantage of mass flow over volumetric flow, which behaves differently for compressible gases.
Also known as