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Exponential Distribution Calculator

The exponential distribution models the continuous time elapsed between independent Poisson events occurring at a constant average rate.

Average number of events per unit time (e.g. 0.5 per hour = 1 event every 2 hours).

Elapsed time or distance threshold.

Calculated Result
63.212%

P(X ≤ 2)

P(X ≤ 2)

63.212%

P(X > 2)

36.788%

Mean Wait Time (1/λ)

2 units

Rate Parameter (λ)

0.5 per unit

Calculation Breakdown

  1. Cumulative Distribution Function P(X ≤ x)F(2) = 1 - e^(-λx) = 1 - e^(-0.5 × 2) = 63.212%.
  2. Reliability / Survival Tail Function P(X > x)S(2) = e^(-λx) = e^(-0.5 × 2) = 36.788%.

Cumulative Probability Over Time (λ = 0.5)

Interactive visualization based on your current inputs

CDF (%)
0.023466992x = 1x = 2x = 3x = 4x = 5Elapsed Time (x)Cumulative Probability P(X ≤ x) (%)

What Is the Exponential Distribution Calculator?

An exponential distribution calculator models continuous time intervals between random Poisson events.

How Does the Exponential Distribution Calculator Work?

Evaluates continuous exponential functions e^(-λx) to compute cumulative and survival probabilities.

Exponential Distribution Calculator Formula & Variables

The core mathematical equation utilized by this calculator is expressed as:

F(x) = 1 - e^(-λx) · S(x) = e^(-λx) · Mean = 1 ÷ λ

Evaluates the exponential CDF for probability of event occurring before x, and the survival function for probability of exceeding x.

How to Use the Exponential Distribution Calculator

  1. Input event rate λ and target elapsed time interval x.

Step-by-Step Example Calculation

Rate λ = 0.5 with interval x = 2

Input Values:

rateLambda:0.5
timeX:2

Understanding Your Result

Shows probability of event occurring within time x, probability of exceeding x, and mean waiting duration.

Factors That Affect the Result

  • Rate parameter λ directly dictates scale and decay speed.

When Should You Use This Calculator?

  • Electronics component lifespan modeling, radioactive decay half-lives, service queue waiting times, and customer service arrival intervals.

Assumptions & Limitations

  • Assumes constant failure or arrival rate over time.

Frequently Asked Questions

Calculation Accuracy & Reference Note

Exact continuous exponential analysis.

Explore more tools and calculators in Statistics Calculators