What is the Lifting Condensation Level?

The LCL is the altitude at which an air parcel lifted dry-adiabatically cools to its dew point, causing water vapor to condense and cloud formation to begin. It represents the theoretical cloud base height for convective clouds.

What formula does this calculator use?

This tool uses the Bolton (1980) approximation: LCL (m) = 125 × (T - Td), where T is the surface temperature and Td is the surface dew point in degrees Celsius. This simple rule-of-thumb is accurate to within a few percent for typical atmospheric conditions.

What inputs do I need?

You need the surface air temperature (dry-bulb) and the dew point temperature, both in degrees Celsius. The dew point must be less than or equal to the temperature. The larger the difference (dew point depression), the higher the LCL.

Can I enter negative temperatures?

Yes. The formula works for any surface temperature and dew point in the typical atmospheric range. Just ensure the dew point does not exceed the air temperature, as that is physically impossible.

How accurate is this estimate?

The Bolton approximation is accurate to within about 1% for dew point depressions less than 30 K. For very dry air (large depression) or extreme temperatures, more precise iterative methods may be warranted.

What is the difference between LCL and CCL?

The LCL (Lifting Condensation Level) is reached by mechanically lifting a parcel; the CCL (Convective Condensation Level) is reached by surface heating alone. For convective clouds, the CCL is more relevant, but the LCL is a useful proxy when surface heating is strong.

Lifting Condensation Level

Name: Lifting Condensation Level
Availability: InStock
Author: Nham Vu

Enter surface temperature and dew point to instantly find the cloud base height (LCL) in meters and feet.

Inputs

Enter surface conditions to compute cloud base height.

Surface Temperature (T)

°C

Dew Point Temperature (T_d)

°C

Formula: LCL (m) = 125 × (T − T_d)
Bolton (1980) dry-adiabatic approximation. Valid for dew point depression < 30 K.

Result

Cloud base height above ground level.

Enter temperature and dew point, then click Calculate.

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Summary

Enter surface temperature and dew point to instantly find the cloud base height (LCL) in meters and feet.

How it works

Enter the surface air temperature in degrees Celsius.
Enter the surface dew point temperature in degrees Celsius.
The tool computes the temperature-dew point depression (T - Td).
Using the Bolton approximation, LCL height = 125 × (T - Td) meters.
Results are displayed instantly in meters and feet above ground level.
Adjust inputs to explore how humidity affects cloud base altitude.

Use cases

Estimate cloud base height for aviation pre-flight planning.
Understand convective storm potential in meteorology studies.
Predict where cumulus clouds will form during the day.
Calculate ceiling height for visual flight rules (VFR) assessment.
Educational tool for atmospheric science and thermodynamics courses.
Quick field estimate for weather observers and outdoor enthusiasts.

Frequently Asked Questions

Last updated: 2026-06-09 · Reviewed by Nham Vu