Mass Flow Rate Converter

Convert mass flow rate between kg/s, kg/h, kg/min, g/s, t/h, lb/s, lb/h, and short ton/h for process, thermal, and industrial throughput work.

Share this calculator

Mass flow rate converter Convert positive mass throughput between metric and imperial units for process equipment, solids handling, thermal systems, and production reporting.

Common presets

Mass rate, not volume rate

This page converts mass per time only. It does not estimate volumetric flow, concentration, or density-driven throughput without separate fluid-property inputs.

Positive throughput model

Mass flow is handled here as a non-negative throughput magnitude. If your process uses a signed convention for direction, convert the magnitude here and apply direction separately.

Enter a mass flow rate Provide a non-negative mass throughput to compare the supported unit systems.

Also in Fluids

Volume Flow Rate Converter

Fluid & Process Systems

Mass flow rate converter: kg/s, kg/h, lb/s, and short ton/h throughput units explained

A mass flow rate converter rewrites the same throughput in the unit your process sheet, thermal model, solids-handling report, or equipment documentation expects. Plants and engineering references often move between SI and US customary flow units, so a clean mass-per-time conversion avoids mixing throughput with unrelated volume-based numbers.

What mass flow rate measures

Mass flow rate measures how much mass passes a point in a given time. The quantity stays the same whether you report it as kilograms per second, kilograms per hour, pounds per second, or short tons per hour.

That makes it a useful reporting unit for process streams, production rates, feeders, and thermal systems where the amount of matter moved matters more than the occupied volume.

ṁ = m / t

Defines mass flow rate as mass divided by time.

1 kg/s = 3,600 kg/h

Links common SI time scales used in production reporting.

ṁ = ρ × A × V

Shows the common relationship between mass flow, density, area, and velocity when those inputs are known.

Why mass flow is different from volume flow

Volumetric flow tells you how much space the stream occupies per unit time. Mass flow tells you how much material is moving. Those are related only when density is known for the conditions that matter.

That distinction becomes especially important for gases, mixed streams, and temperature-dependent liquids. A converter can translate the mass-rate units directly, but it cannot infer the volumetric rate without a separate density assumption.

Watch the ton label carefully

Metric tonne per hour and short ton per hour are not the same. Industrial pages often shorten both to ton/h, which can create avoidable errors when a site mixes SI and US customary reporting.

This page treats the imperial ton entry as short ton per hour and keeps the metric `t/h` entry separate so the throughput stays unambiguous.

Further reading

Frequently asked questions

What is the difference between mass flow and volumetric flow?

Mass flow measures mass per unit time, while volumetric flow measures volume per unit time. You need density to convert between them.

 Is ton/h the same as tonne per hour?

Not always. In this converter, the imperial ton entry means short ton per hour, while the metric entry `t/h` means tonne per hour. Those are different quantities.

 Why do engineers use kg/h instead of kg/s?

Both are valid. `kg/s` is convenient in physics and transport equations, while `kg/h` often fits plant throughput, equipment nameplates, and production reports more naturally.

 Can this page calculate mass flow from pipe size and velocity?

No. This page converts a stated mass flow only. To calculate mass flow from velocity, area, and density, you need those separate inputs and the underlying process assumptions.

Related

More from nearby categories

These related calculators come from the same leaf category, nearby sibling categories, or the same top-level topic.

Volume Flow Rate Converter

Convert volumetric flow rate between m³/s, m³/h, L/s, L/min, mL/s, US and UK gallons per minute, ft³/s, ft³/min, and barrels per day.

Open calculator

Angular Velocity Converter

Convert signed angular velocity between rad/s, rad/min, mrad/s, deg/s, deg/min, RPM, RPS, and rev/h for engineering, controls, and motion work.

Open calculator

Acceleration Converter

Convert signed linear acceleration between m/s², cm/s², mm/s², ft/s², in/s², g, Gal, and km/h/s for engineering, transport, and physics work.

Open calculator

Angular Acceleration Converter

Convert signed angular acceleration between rad/s², rad/min², deg/s², deg/min², rpm/s, rpm/min, and rev/s² for motion-control and engineering calculations.

Open calculator

Privacy choices

If you allow analytics, we may use Google Analytics and Microsoft Clarity to better understand how the site is used. Analytics remain off unless you accept.