Offline
No internet, no account required.
ASHRAE
Validated against the standard.
PDF export
Pro-only. Generate professional reports.
$2.99 Pro
Lifetime unlock. No subscriptions.
How it works
Enter your values
Type in your inputs — the app fills code tables and constants for you, so there's nothing to look up.
Get a code-checked result
Instant answer with a clear PASS / FAIL and the exact ASHRAE reference behind every number.
Save & export
Keep a history of calculations and export a clean PDF report to share or attach to a permit (Pro).
What this calculator does
Psychrometrics is the study of moist air, and it underpins every cooling, heating, and dehumidification decision. This app turns any two air properties into all the rest — dry-bulb, wet-bulb, relative humidity, dew point, humidity ratio, and enthalpy — without a paper psych chart.
The properties it relates
- Dry-bulb temperature — what a normal thermometer reads.
- Wet-bulb temperature — reflects evaporative cooling and moisture.
- Relative humidity and dew point — how close the air is to saturation.
- Humidity ratio and enthalpy — the moisture content and total heat used in load and coil calculations.
Worked example
Enter 75°F dry-bulb and 50% relative humidity and the app returns the matching wet-bulb (about 62.5°F), dew point (about 55°F), and the enthalpy and humidity ratio used to size a cooling coil.
Related calculators
Feed enthalpy and airflow into the airflow CFM calculator and the heat load calculator.
Psychrometric FAQ
What inputs does it need?
Any two independent properties — for example dry-bulb plus relative humidity, or dry-bulb plus wet-bulb — and the app computes the rest at your chosen barometric pressure.
Does altitude matter?
Yes. Air properties depend on barometric pressure, so the app lets you set elevation or pressure for accurate results at altitude.
Why is enthalpy useful?
Enthalpy captures both sensible and latent heat, so the difference in enthalpy across a coil, multiplied by airflow, gives the total cooling capacity.
Does it work offline?
Yes, it runs 100% offline with no account. Free with rewarded ads; a one-time $2.99 Pro unlock adds PDF export and saved history.
Get Psychrometric on your phone
Free with rewarded ads · $2.99 lifetime Pro · iOS & Android. Works 100% offline on the job site.