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Calcimator

CAPE and CIN Calculator

Calculate Convective Available Potential Energy (CAPE) and Convective Inhibition (CIN) from parcel and environmental temperatures at multiple pressure levels.

Inputs

°F
°F
°F
°F
°F
°F
°F
°F
mb
mb

Results

CAPE

594 J/kg

CIN

0 J/kg

Max Updraft Speed34.5 m/s
Storm PotentialSlight — Weak Storms Possible
CIN AssessmentNone
How to Use This Calculator
  1. Enter temperature (°C) for the air parcel and environment at each pressure level: surface, 850 mb, 700 mb, and 500 mb.
  2. Set LFC Pressure (mb) — the Level of Free Convection where the parcel becomes buoyant.
  3. Set EL Pressure (mb) — the Equilibrium Level where the parcel returns to neutral buoyancy.
  4. Review CAPE (J/kg): below 1000 = weak instability, 1000–2500 = moderate, 2500–3500 = large, 3500+ = extreme.
  5. Check CIN (J/kg) — values above 200 indicate a strong cap that may suppress storms even with high CAPE.

How the result changes with Parcel Temp (850 mb)

Parcel Temp (850 mb)CAPECIN
-24338 J/kg1,894 J/kg
-9338 J/kg1,126 J/kg
9338 J/kg205 J/kg
24901 J/kg0 J/kg

What each input means

Parcel Temp (Surface)
Lifted parcel temperature at the surface level in °C.
Environment Temp (Surface)
Observed environmental temperature at the surface in °C.
Parcel Temp (850 mb)
Lifted parcel temperature at 850 mb (~1,500 m) in °C.
Environment Temp (850 mb)
Environmental temperature at 850 mb from sounding data in °C.
Parcel Temp (700 mb)
Lifted parcel temperature at 700 mb (~3,000 m) in °C.
Environment Temp (700 mb)
Environmental temperature at 700 mb from sounding data in °C.
Parcel Temp (500 mb)
Lifted parcel temperature at 500 mb (~5,500 m) in °C.
Environment Temp (500 mb)
Environmental temperature at 500 mb from sounding data in °C.
LFC Pressure
Level of Free Convection in mb — the altitude where the parcel becomes buoyant.
Equilibrium Level
Equilibrium Level in mb — the altitude where parcel temperature equals environment temperature.

What each result means

CAPE
Total convective energy available for thunderstorm updrafts.
CIN
Convective inhibition — energy barrier that must be overcome for storm initiation.

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Parcel Temp (Surface) = 30, Environment Temp (Surface) = 28, Parcel Temp (850 mb) = 18, Environment Temp (850 mb) = 15 = 10 input(s) provided
  2. Calculate CAPE
    CAPE = energy
    594 = 594
  3. Calculate CIN
    CIN = Math
    0 = 0
  4. Calculate Max Updraft Speed
    Max Updraft Speed
    34.5 = 34.5
  5. Calculate Storm Potential
    Storm Potential
    Slight — Weak Storms Possible = Slight — Weak Storms Possible

Engine last updated . Checked against 2 independently-derived tests — how we verify calculators.

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