POISSON.DIST
Quirk foundCategory: Statistical · Last tested 2026-09-01
Real compatibility results for the POISSON.DIST function: executed in Excel for the web, Google Sheets and LibreOffice Calc, with desktop Excel behavior from Microsoft’s official documentation (we do not run desktop Excel — Excel for the web is a different application and is executed separately). Syntax and links to that documentation are below.
Support matrix
| Engine | Documented | Live-tested | Verdict |
|---|---|---|---|
| Excel (desktop) | Yes | No — documented only | n/a |
| Excel for the web | — | Yes (recalc, 2026-09-01) | Supported, behaves as documented |
| Google Sheets | Yes | Yes (Drive import, 2026-08-31) | Supported, behaves as documented |
| LibreOffice Calc | Yes | Yes (25.8.7.3, 2026-08-31) | Quirk found |
LibreOffice version history
We executed the same test cases under each LibreOffice release to show exactly when POISSON.DIST’s support changed — not documentation claims, real results.
| LibreOffice version | Verdict | Tested |
|---|---|---|
| 24.2.0.3 | Quirk found | 2026-08-31 |
| 24.8.7.2 | Quirk found | 2026-08-31 |
| 25.2.0.3 | Quirk found | 2026-08-31 |
| 25.8.7.3 | Quirk found | 2026-08-31 |
Why isn't POISSON.DIST working in LibreOffice?
POISSON.DIST exists in LibreOffice 25.8.7.3, but it is not a drop-in match for
Excel — our executed tests found real behavioral differences (detailed in the test results on this
page). If a formula that works in Excel or Google Sheets misbehaves in LibreOffice, compare your usage
against the failing cases above before assuming your data is wrong.
Discovered quirks
-
=POISSON.DIST(-1,A3,TRUE) on
LibreOffice Calc returned
#VALUE!, but the documented/expected
result is #NUM!.
Provenance
Microsoft documents: "If x < 0, POISSON.DIST returns the #NUM! error value."; MISMATCH vs expected: expected '#NUM!', got '#VALUE!'
-
=POISSON.DIST(A2,-5,TRUE) on
LibreOffice Calc returned
#VALUE!, but the documented/expected
result is #NUM!.
Provenance
Microsoft documents: "If mean < 0, POISSON.DIST returns the #NUM! error value."; MISMATCH vs expected: expected '#NUM!', got '#VALUE!'
Executed test cases
Excel for the web (executed 2026-09-01 via OneDrive recalculation)
These values come from Excel for the web, not from desktop Excel. They are two different implementations of the calculation engine, and this run measured only the web one: the corpus was uploaded to OneDrive as .xlsx, recalculated by Excel for the web on open, and downloaded again for readback. Excel for the web is a rolling service with no pinnable version, so the run is identified by its date. Where a value here disagrees with the Expected column — which is Microsoft’s documentation of the desktop product — we cannot tell you whether the web engine diverges from the desktop one or the documentation is wrong about both, because we do not run desktop Excel.
| Formula | Description | Result | Expected | Verdict |
|---|---|---|---|---|
| =ROUND(POISSON.DIST(A2,A3,TRUE),6) | Microsoft's documented worked example, cumulative form | 0.124652 | 0.124652ProvenanceMicrosoft publishes =POISSON.DIST(A2,A3,TRUE) = 0.124652 -- the same example, the same data and the same figure as the compatibility function POISSON, whose page prints the identical table and shares the identical formula images. DERIVATION with mpmath at 50 digits, straight from the two documented formulas -- mass e^(-lambda) * lambda^x / x!, cumulative the sum of that over k = 0..x -- and not from any statistics library: e^-5 = 0.006737946999085467..., so the mass at x = 2 is e^-5 * 25/2 = 0.08422433748856832... and the cumulative value is e^-5 * (1 + 5 + 12.5) = e^-5 * 18.5 = 0.12465201948308113... Microsoft's page was re-read live on 2026-08-31 at https://support.microsoft.com/en-us/excel/functions/poisson-dist-function (the /en-us/office/<name>-function-<guid> path was returning Microsoft's 'Sorry, the page you're looking for can't be found' body throughout this batch, and the working path serves an 87 KB stub about half the time, so pages were fetched with retries until the payload exceeded 150 KB). |
Matched |
| =ROUND(POISSON.DIST(A2,A3,FALSE),6) | The same example in its non-cumulative form | 0.084224 | 0.084224ProvenanceMicrosoft publishes =POISSON.DIST(A2,A3,FALSE) = 0.084224. e^-5 * 25/2 = 0.08422433748856832... |
Matched |
| =ROUND(POISSON.DIST(A2,A3,FALSE),12) | The mass value carried to twelve decimal places | 0.084224337489 | 0.084224337489ProvenanceAsserted at twelve places from the same derivation: 0.084224337489. |
Matched |
| =ROUND(POISSON.DIST(2,5,TRUE)-POISSON(2,5,TRUE),12) | The modern and compatibility spellings must agree exactly | 0 | 0ProvenancePOISSON's page carries Microsoft's standard compatibility notice pointing at POISSON.DIST as its replacement, and both pages publish the same two figures from the same two formula images. This case checks the two names against each other inside the engine: the difference must be exactly zero. It is the cheapest possible test of the claim that the rename changed nothing but the name. |
Matched |
| =POISSON.DIST(-1,A3,TRUE) | A negative number of events, which the page excludes | #NUM! | #NUM!ProvenanceMicrosoft documents: "If x < 0, POISSON.DIST returns the #NUM! error value." |
Matched |
| =POISSON.DIST(A2,-5,TRUE) | A negative mean | #NUM! | #NUM!ProvenanceMicrosoft documents: "If mean < 0, POISSON.DIST returns the #NUM! error value." |
Matched |
| =POISSON.DIST("x",A3,TRUE) | A non-numeric x | #VALUE! | #VALUE!ProvenanceMicrosoft documents: "If x or mean is nonnumeric, POISSON.DIST returns the #VALUE! error value." |
Matched |
Google Sheets (executed 2026-08-31 via Drive import)
Google Sheets is a rolling service with no pinnable version, so this run is identified by its date. The corpus was imported to Drive as .xlsx, recalculated by Sheets, and exported back for readback.
| Formula | Description | Result | Expected | Verdict |
|---|---|---|---|---|
| =ROUND(POISSON.DIST(A2,A3,TRUE),6) | Microsoft's documented worked example, cumulative form | 0.124652 | 0.124652ProvenanceMicrosoft publishes =POISSON.DIST(A2,A3,TRUE) = 0.124652 -- the same example, the same data and the same figure as the compatibility function POISSON, whose page prints the identical table and shares the identical formula images. DERIVATION with mpmath at 50 digits, straight from the two documented formulas -- mass e^(-lambda) * lambda^x / x!, cumulative the sum of that over k = 0..x -- and not from any statistics library: e^-5 = 0.006737946999085467..., so the mass at x = 2 is e^-5 * 25/2 = 0.08422433748856832... and the cumulative value is e^-5 * (1 + 5 + 12.5) = e^-5 * 18.5 = 0.12465201948308113... Microsoft's page was re-read live on 2026-08-31 at https://support.microsoft.com/en-us/excel/functions/poisson-dist-function (the /en-us/office/<name>-function-<guid> path was returning Microsoft's 'Sorry, the page you're looking for can't be found' body throughout this batch, and the working path serves an 87 KB stub about half the time, so pages were fetched with retries until the payload exceeded 150 KB). |
Matched |
| =ROUND(POISSON.DIST(A2,A3,FALSE),6) | The same example in its non-cumulative form | 0.084224 | 0.084224ProvenanceMicrosoft publishes =POISSON.DIST(A2,A3,FALSE) = 0.084224. e^-5 * 25/2 = 0.08422433748856832... |
Matched |
| =ROUND(POISSON.DIST(A2,A3,FALSE),12) | The mass value carried to twelve decimal places | 0.08422433749 | 0.084224337489ProvenanceAsserted at twelve places from the same derivation: 0.084224337489. |
Matched |
| =ROUND(POISSON.DIST(2,5,TRUE)-POISSON(2,5,TRUE),12) | The modern and compatibility spellings must agree exactly | 0 | 0ProvenancePOISSON's page carries Microsoft's standard compatibility notice pointing at POISSON.DIST as its replacement, and both pages publish the same two figures from the same two formula images. This case checks the two names against each other inside the engine: the difference must be exactly zero. It is the cheapest possible test of the claim that the rename changed nothing but the name. |
Matched |
| =POISSON.DIST(-1,A3,TRUE) | A negative number of events, which the page excludes | #NUM! | #NUM!ProvenanceMicrosoft documents: "If x < 0, POISSON.DIST returns the #NUM! error value." |
Matched |
| =POISSON.DIST(A2,-5,TRUE) | A negative mean | #NUM! | #NUM!ProvenanceMicrosoft documents: "If mean < 0, POISSON.DIST returns the #NUM! error value." |
Matched |
| =POISSON.DIST("x",A3,TRUE) | A non-numeric x | #VALUE! | #VALUE!ProvenanceMicrosoft documents: "If x or mean is nonnumeric, POISSON.DIST returns the #VALUE! error value." |
Matched |
LibreOffice Calc 25.8.7.3 (tested 2026-08-31)
| Formula | Description | Result | Expected | Verdict |
|---|---|---|---|---|
| =ROUND(POISSON.DIST(A2,A3,TRUE),6) | Microsoft's documented worked example, cumulative form | 0.124652 | 0.124652ProvenanceMicrosoft publishes =POISSON.DIST(A2,A3,TRUE) = 0.124652 -- the same example, the same data and the same figure as the compatibility function POISSON, whose page prints the identical table and shares the identical formula images. DERIVATION with mpmath at 50 digits, straight from the two documented formulas -- mass e^(-lambda) * lambda^x / x!, cumulative the sum of that over k = 0..x -- and not from any statistics library: e^-5 = 0.006737946999085467..., so the mass at x = 2 is e^-5 * 25/2 = 0.08422433748856832... and the cumulative value is e^-5 * (1 + 5 + 12.5) = e^-5 * 18.5 = 0.12465201948308113... Microsoft's page was re-read live on 2026-08-31 at https://support.microsoft.com/en-us/excel/functions/poisson-dist-function (the /en-us/office/<name>-function-<guid> path was returning Microsoft's 'Sorry, the page you're looking for can't be found' body throughout this batch, and the working path serves an 87 KB stub about half the time, so pages were fetched with retries until the payload exceeded 150 KB). |
Matched |
| =ROUND(POISSON.DIST(A2,A3,FALSE),6) | The same example in its non-cumulative form | 0.084224 | 0.084224ProvenanceMicrosoft publishes =POISSON.DIST(A2,A3,FALSE) = 0.084224. e^-5 * 25/2 = 0.08422433748856832... |
Matched |
| =ROUND(POISSON.DIST(A2,A3,FALSE),12) | The mass value carried to twelve decimal places | 0.084224337489 | 0.084224337489ProvenanceAsserted at twelve places from the same derivation: 0.084224337489. |
Matched |
| =ROUND(POISSON.DIST(2,5,TRUE)-POISSON(2,5,TRUE),12) | The modern and compatibility spellings must agree exactly | 0 | 0ProvenancePOISSON's page carries Microsoft's standard compatibility notice pointing at POISSON.DIST as its replacement, and both pages publish the same two figures from the same two formula images. This case checks the two names against each other inside the engine: the difference must be exactly zero. It is the cheapest possible test of the claim that the rename changed nothing but the name. |
Matched |
| =POISSON.DIST(-1,A3,TRUE) | A negative number of events, which the page excludes | #VALUE! | #NUM!ProvenanceMicrosoft documents: "If x < 0, POISSON.DIST returns the #NUM! error value." |
Mismatch |
| =POISSON.DIST(A2,-5,TRUE) | A negative mean | #VALUE! | #NUM!ProvenanceMicrosoft documents: "If mean < 0, POISSON.DIST returns the #NUM! error value." |
Mismatch |
| =POISSON.DIST("x",A3,TRUE) | A non-numeric x | #VALUE! | #VALUE!ProvenanceMicrosoft documents: "If x or mean is nonnumeric, POISSON.DIST returns the #VALUE! error value." |
Matched |
Docs & syntax
- Excel (desktop): official documentation
- Google Sheets: official documentation
- LibreOffice Calc: official documentation
Where POISSON.DIST behaves differently
- Your function exists but your file cannot say so: _xlfn storage tokens
Executed: eight IM* functions LibreOffice implements return #NAME? on all four builds because it cannot read Excel's _xlfn. token for them, while COT and CSC only work under that same prefix. Eleven LibreOffice aliases are erased by its own exporter, and a token change between 24.2 and 24.8 makes a 24.8-written file open as #NAME? in 24.2.