CALCULATORS / UNITS AND DIMENSIONAL REASONING

Volumetric to mass flow rate calculator

Volumetric-to-mass flow at constant density.

units-flow.napkin / editable

SCENARIO COMPARISON

Compare the numbers.

This source describes an analytical model. Its quantities and checks are the view.

Scenario	volumeFlowm^3/s	massFlowkg/s
	0.000166667	0.166667
	0.000133333	0.133333

All calculated quantities are listed with the inputs. Switch to Source to inspect the equations.

SCENARIOS / CALCULATED VALUESSAME SOURCE

Change an input to see the consequences.

pump flow budget10.00 L/min✓ passes

BASELINE INPUTS

flow10 L/mindensity1000 kg/m^3

CALCULATED

volumeFlow0.00016667 m^3/s

massFlow0.16667 kg/s

Edits change the baseline source.

THE SOURCE

Edits below update the same model.

# Flow-rate conversion
# Scope: Volumetric-to-mass flow at constant density.
# Status: illustrative worked example; engineering review pending.
# Inputs are example values. Checks are editable example requirements, not standards.

flow = 10 L/min
density = 1000 kg/m^3

volumeFlow := flow [m^3/s]
massFlow := density * flow [kg/s]

check pump flow budget: flow <= 15 L/min

scenario alternative: flow = 8 L/min

Calculated from your source · not saved

Baseline · Baseline

pump flow budget10.00 L/min ✓ passes

alternative · alternative

pump flow budget8.00 L/min ✓ passes

Illustrative first-order example. Checks are editable requirements, not design standards. The broader topic may require additional equations, data, and validation.

Formula and units

This example uses the following equations. Input names and units match the editable source above.

volume flow: volumeFlow = flow [m^3/s]
mass flow: massFlow = density * flow [kg/s]

Original worked example

These are the baseline values in the downloadable source. Edits above let you test your own values.

Given

flow: 10 L/min
density: 1000 kg/m^3

Calculated

volume flow: 0.000166667 m^3/s
mass flow: 0.166667 kg/s

Assumptions and limits

Volumetric-to-mass flow at constant density.

The requirement checks use the limits written in this example. Passing a check does not establish that the model covers every load, material behavior, or operating condition in a real design.

Download this .napkin example ↓

Take it further with your agent

Napkin keeps the inputs, equations, checks and assumptions together in one study. Your agent sets it up; you change the numbers.

Try with Claude ↗

codex 'Use Napkin (https://napkin.engineering/mcp, or the local Napkin plugin) to build a study: Flow-rate conversion. Inputs: volume or mass flow; density when needed. Outputs: m3/s, L/min, CFM or mass flow. Model scope: Dimensional analysis and explicit reference conventions. Read napkin_capabilities and the current snapshot. Ask me for the values that matter, label assumptions with units, author .napkin source, validate it and apply it with napkin_source using the current revision, then open the study. Add checks for the limits I supply. Keep unsupported analyses explicit.'

Claude needs the Napkin connector; Codex needs the Napkin plugin. Set up your agent ↗

The broader study

The topic brief below describes the broader scope. The worked example above states the particular calculation it implements.

Inputs: volume or mass flow, density when needed
Outputs: m3/s, L/min, CFM or mass flow
Modes: convert, solve-for
Drawing: Quantity diagram

EXECUTABLE WORKED EXAMPLE · FIRST-ORDER MODEL · CHECK THE SCOPE & ASSUMPTIONS