🌡️ Sea-Level Pressure Calculator
Enter your barometer's station pressure, your altitude and the temperature to get the equivalent sea-level pressure.
Sea-level pressure
1060.7 hPa
31.32 inHg · +60.7 hPa correction
Reading
Higher than standard (fair)
Barometers read the actual (station) pressure, which is lower at altitude. To compare readings between places, weather services reduce them to sea level: P₀ = P × (1 − 0.0065·h / (T + 0.0065·h + 273.15))⁻⁵·²⁵⁷. Standard sea-level pressure is 1013.25 hPa (29.92 inHg). 🔒 In your browser.
How the sea-level pressure calculator works
A barometer reads the actual air pressure where it sits (station pressure), which falls as you climb — so readings from places at different altitudes can't be compared directly. Weather services "reduce" them to a common baseline, sea level, using the barometric formula with the observed temperature: P₀ = P × (1 − 0.0065·h / (T + 0.0065·h + 273.15))⁻⁵·²⁵⁷, where h is altitude in metres and T the temperature in °C. The result is what forecasts and pressure maps quote, and it's how you spot highs and lows.
The correction grows with altitude — roughly 12 hPa per 100 m near the surface — so getting your elevation right matters. This is the standard temperature-dependent reduction; official station algorithms may use a 12-hour mean temperature and other refinements, but this gives an accurate everyday figure. Standard sea-level pressure is 1013.25 hPa (29.92 inHg).
Frequently asked questions
What is the difference between station and sea-level pressure?
Station pressure is the actual pressure measured at your location and altitude; sea-level pressure adjusts it to what it would be at sea level, so readings from different elevations can be compared. Forecasts always quote sea-level pressure.
How do I convert station pressure to sea level?
Use the barometric formula with your altitude and temperature: P₀ = P × (1 − 0.0065·h / (T + 0.0065·h + 273.15))⁻⁵·²⁵⁷. Near the surface it adds roughly 12 hPa per 100 m of elevation. This tool does it for you.
Why does altitude affect barometric pressure?
Air pressure comes from the weight of the atmosphere above you. The higher you go, the less air is overhead, so the pressure drops — about 1 hPa per 8 m near sea level. That's why raw barometer readings must be corrected to compare weather between locations.
What is standard sea-level pressure?
1013.25 hPa, equal to 29.92 inHg or 760 mmHg. Readings above that suggest higher pressure (typically fair weather) and below it lower pressure (often more unsettled conditions).
Does temperature matter for the correction?
Yes — colder air is denser, so the pressure changes faster with height, making the correction larger. This calculator includes the observed temperature; simpler altitude-only formulas are less accurate, especially at higher elevations.