Mixing Ratio Calculator

Estimate actual and saturated mixing ratio plus dew point, wet bulb, vapor pressure and enthalpy with a pressure-aware local calculation.

Moist-air mixing ratio

Mixing ratio is water-vapor mass per mass of dry air, so station pressure matters. It is not the same quantity as absolute humidity in g/m³.

Air temperature (°C)

Relative humidity (%)

Station pressure (hPa)

Psychrometric Calculator Dew Point Relative Humidity Absolute Humidity Wet Bulb

Mixing-ratio result

—Actual mixing ratio

—Saturated mixing ratio

—Vapor pressure

—Dew point

Atmospheric moisture cross-check

Recompute vapor pressure, saturation mixing ratio and specific humidity from temperature, RH and pressure.

Humidity evidence

Metric	Value	Meaning

One moist-air state, several related properties

Relative humidity, dew point, wet bulb, vapor pressure, absolute humidity and humidity ratio describe different parts of the same moisture state. WebToolArc keeps the selected inputs visible and shows related outputs together instead of treating the terms as interchangeable.

Accuracy boundary

These browser calculations use standard psychrometric approximations. Real measurements can differ because of sensor calibration, station pressure, ventilation, radiation, local gradients and the exact saturation-vapor-pressure formulation. Use calibrated instruments and applicable engineering or meteorological standards when decisions require certified measurements.

Practical guide and verification

Confirm this is moist-air mixing ratio

This page calculates water-vapor mass relative to dry-air mass from temperature, relative humidity, and pressure. It is not a general recipe ratio such as paint, fuel, concrete, or two-liquid mixing, even though those tasks use similar wording.

Use station pressure when describing the actual air parcel

Mixing ratio depends on vapor pressure and total pressure. Substituting sea-level-reduced pressure for a high-altitude station can shift the result because the parcel’s actual pressure is different. Match the pressure input to the state being described.

Check relative humidity bounds and units

Relative humidity is entered as percent, temperature uses the displayed temperature unit, and pressure uses hPa in the core workflow. A value such as 0.60 means 0.60 percent here, not 60 percent, unless converted before entry.

Cross-check with dew point and saturation ratio

The computed vapor pressure should be below saturation pressure when RH is below 100 percent. The actual mixing ratio should likewise stay below the saturation mixing ratio. The displayed dew point offers another useful consistency check.

Treat the formulas as engineering approximations

Psychrometric formulas depend on saturation-vapor-pressure approximations and assumptions about moist air. For calibration, standards work, or extreme conditions, compare with the model and pressure conventions required by the relevant engineering reference.