HPDash:Racing Density Altitude

HPDash DA puts accurate, real-time density altitude in your pocket — built for drag racers, tuners, and anyone who needs to know what the air is doing right now.

Density altitude (DA) is the single number that tells you how your engine will perform today. HPDash DA computes it from first principles using your phone's barometric pressure sensor for true local station pressure, your GPS location, and live temperature and dewpoint from the U.S. National Weather Service — so the reading reflects the actual air where you are, not a rough estimate.

WHAT YOU GET
• Live density altitude in feet and meters
• Relative air density (%)
• Full air breakdown: station pressure, temperature, dewpoint, humidity, air density
• ENGINE POWER (SAE J1349): the dyno correction factor and % of standard power, plus dry air pressure and grains of water (absolute humidity)
• Enter your baseline horsepower to see the power the current air will support

ACCURATE BY DESIGN
HPDash DA prefers your phone's barometer for true station pressure (the same input a weather station uses) and pulls temperature and dewpoint from official NWS observations. The result is a first-principles density altitude — not a back-of-the-napkin approximation.

FREE, WITH AN OPTIONAL UPGRADE
Free to use, supported by ads. Go ad-free for $2.99/year and unlock automatic weather refresh so your numbers stay live while you work.

NOTES
• U.S. coverage (weather data is provided by the U.S. National Weather Service).
• For informational and motorsport/recreational use only — not for aviation or navigation.

HPDash — tools for people who tune. hpdash.com