EXPONDIST Function (LibreOffice Calc — Legacy)
The EXPONDIST function is the legacy version of EXPON.DIST. It returns the exponential distribution (PDF or CDF) and is maintained for compatibility with older spreadsheets.
Compatibility
▾| Excel | ✔ |
| Gnumeric | ✔ |
| Google_sheets | ✔ |
| Libreoffice | ✔ |
| Numbers | ✔ |
| Onlyoffice | ✔ |
| Openoffice | ✔ |
| Wps | ✔ |
| Zoho | ✔ |
What the EXPONDIST Function Does ▾
- Computes the exponential distribution
- Supports PDF and CDF
- Models time between events in a Poisson process
- Fully equivalent to EXPON.DIST
Syntax ▾
EXPONDIST(x; lambda; cumulative)
Arguments
-
x:
Time or value at which to evaluate the distribution (x ≥ 0). -
lambda:
Rate parameter (λ > 0). -
cumulative:
- TRUE → CDF
- FALSE → PDF
Mathematical Definitions ▾
PDF (cumulative = FALSE)
[ f(x) = \lambda e^{-\lambda x} ]
CDF (cumulative = TRUE)
[ F(x) = 1 - e^{-\lambda x} ]
Basic Examples ▾
PDF example
=EXPONDIST(2; 0.5; FALSE)
→ 0.18393972
CDF example
=EXPONDIST(2; 0.5; TRUE)
→ 0.63212056
Probability event occurs within 5 units of time
=EXPONDIST(5; lambda; TRUE)
Density at x = 0
=EXPONDIST(0; 0.2; FALSE)
→ 0.2
Advanced Examples ▾
Reliability modeling (failure probability)
=EXPONDIST(t; lambda; TRUE)
Survival probability
=1 - EXPONDIST(t; lambda; TRUE)
Probability between two times
=EXPONDIST(b; λ; TRUE) - EXPONDIST(a; λ; TRUE)
Generate exponential random variable
=-LN(1 - RAND()) / lambda
Queueing theory (arrival times)
=EXPONDIST(t; arrival_rate; TRUE)
Edge Cases and Behavior Details ▾
EXPONDIST returns a number
Behavior details
- x must be ≥ 0
- lambda must be > 0
- PDF ≥ 0
- CDF ∈ [0, 1]
- Identical to EXPON.DIST except for naming
Invalid input → Err:502
Common Errors and Fixes ▾
Err:502 — Invalid argument
Cause:
- lambda ≤ 0
- x < 0
- Non‑numeric input
Fix:
- Ensure x ≥ 0
- Ensure lambda > 0
- Wrap with VALUE() if needed
Unexpected CDF values
Cause:
- Unit mismatch (seconds vs minutes vs hours)
Fix:
- Normalize units
Best Practices ▾
- Prefer EXPON.DIST for modern spreadsheets
- Use EXPONDIST only for legacy compatibility
- Validate units (time, rate)
- Use RAND‑based inverse transform for simulation
- Document λ and time units clearly
EXPONDIST is fully equivalent to EXPON.DIST — the only difference is naming. Use EXPON.DIST for new models and keep EXPONDIST for backward compatibility.
Related Patterns and Alternatives ▾
- EXPON.DIST — modern version
- POISSON.DIST — event counts
- GAMMA.DIST — generalization of exponential
- WEIBULL.DIST — flexible lifetime modeling
- EXP — exponential function
By mastering EXPONDIST, you can maintain compatibility with older spreadsheets while still modeling exponential processes accurately.