CALCULATORS / UNITS AND DIMENSIONAL REASONING

Gauge to absolute pressure calculator

Gauge pressure plus an explicitly supplied atmospheric reference.

units-pressure.napkin / editable

SCENARIO COMPARISON

Compare the numbers.

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

Scenario	absolutePa	psipsi
	301325	43.7035
	261325	37.902

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.

absolute pressure positive301325.00 Pa✓ passes

BASELINE INPUTS

gauge2 baratmosphere101325 Pa

CALCULATED

absolute301330 Pa

psi43.703 psi

Edits change the baseline source.

THE SOURCE

Edits below update the same model.

# Pressure conversion
# Scope: Gauge pressure plus an explicitly supplied atmospheric reference.
# Status: illustrative worked example; engineering review pending.
# Inputs are example values. Checks are editable example requirements, not standards.

gauge = 2 bar
atmosphere = 101325 Pa

absolute := gauge + atmosphere [Pa]
psi := absolute [psi]

check absolute pressure positive: absolute > 0 Pa

scenario alternative: gauge = 1.6 bar

Calculated from your source · not saved

Baseline · Baseline

absolute pressure positive301325.00 Pa ✓ passes

alternative · alternative

absolute pressure positive261325.00 Pa ✓ 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.

absolute: absolute = gauge + atmosphere [Pa]
psi: psi = absolute [psi]

Original worked example

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

Given

gauge: 2 bar
atmosphere: 101325 Pa

Calculated

absolute: 301325 Pa
psi: 43.7035 psi

Assumptions and limits

Gauge pressure plus an explicitly supplied atmospheric reference.

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: Pressure conversion. Inputs: pressure; absolute or gauge reference. Outputs: Pa, bar, psi; reference-aware result. 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: pressure, absolute or gauge reference
Outputs: Pa, bar, psi, reference-aware result
Modes: convert, solve-for
Drawing: Quantity diagram

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