CALCULATORS / UNITS AND DIMENSIONAL REASONING

Mass to weight calculator: kg to newtons

Local weight from mass and supplied gravitational acceleration.

units-force-mass-weight.napkin / editable

SCENARIO COMPARISON

Compare the numbers.

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

Scenario	weightN
	98.1
	78.48

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.

lifting budget98.10 N✓ passes

BASELINE INPUTS

mass10 kggravity9.81 m/s^2

CALCULATED

weight98.1 N

Edits change the baseline source.

THE SOURCE

Edits below update the same model.

# Mass, weight and force
# Scope: Local weight from mass and supplied gravitational acceleration.
# Status: illustrative worked example; engineering review pending.
# Inputs are example values. Checks are editable example requirements, not standards.

mass = 10 kg
gravity = 9.81 m/s^2

weight := mass * gravity [N]

check lifting budget: weight <= 150 N

scenario alternative: mass = 8 kg

Calculated from your source · not saved

Baseline · Baseline

lifting budget98.10 N ✓ passes

alternative · alternative

lifting budget78.48 N ✓ 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.

weight: weight = mass * gravity [N]

Original worked example

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

Given

mass: 10 kg
gravity: 9.81 m/s^2

Calculated

weight: 98.1 N

Assumptions and limits

Local weight from mass and supplied gravitational acceleration.

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: Mass, weight and force. Inputs: mass or force; gravity. Outputs: weight or mass; local gravity assumption. 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: mass or force, gravity
Outputs: weight or mass, local gravity assumption
Modes: convert, solve-for
Drawing: Quantity diagram

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