# getguesstimate/guesstimate-app

Create Fermi Estimates and Perform Monte Carlo Estimates

Repository: https://github.com/getguesstimate/guesstimate-app
Canonical: https://ross.abutalabs.com/products/guesstimate-app
Homepage: http://getguesstimate.com/
Language: TypeScript
License: MIT
License Family: permissive
Last push: 2026-08-12T06:03:54+00:00

## Health v2 (maintenance only)
Score: 66/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 97, release rhythm 8, longevity 100
- inputs: {"age_days": 4030, "days_push": 21, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2367, forks 128 (observed 2026-08-28T04:06:41.596281+00:00)

## What it is
Guesstimate is a web-based spreadsheet-like tool for creating Fermi estimates using Monte Carlo simulation. Users enter ranges and distributions as cell values, and it runs 5000-sample simulations to produce confidence intervals for computed metrics.

## Use cases
- estimate uncertain quantities with confidence intervals
- run monte carlo simulations on spreadsheet-like models
- build fermi estimates with ranges instead of point values
- propagate uncertainty through mathematical models
- visualize probability distributions of calculated metrics
- model business or scientific forecasts with uncertain inputs

## When to choose
- you need uncertainty-aware estimates rather than single point values
- you want an Excel-like interface with distributions as inputs
- you need quick quantitative modeling without writing code

## When to avoid
- you need exact deterministic calculations rather than sampled estimates
- you require advanced spreadsheet features like imports, macros, or collaboration
- you need high-performance simulation with millions of samples

## Facets
- artifact type: application
- maturity: maintenance
- function: simulation, data-visualization, math
- domain: data-science, analytics, developer-tools, mathematics
- platform: cross-platform
- tags: monte-carlo, fermi-estimation, spreadsheet, uncertainty, typescript, react, web-server

## Member repositories
- getguesstimate/guesstimate-app (main) score 66

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:06:41.596281+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T02:35:57.423071+00:00, confidence not recorded.
  - readme: https://github.com/getguesstimate/guesstimate-app (fetched 2026-08-28T04:06:41.596281+00:00, sha 82a930b9df43)
  - homepage: http://getguesstimate.com/ (fetched 2026-08-29T10:16:39.750801+00:00, sha 0eff95536625)
- Data as of 2026-08-30T08:39:29.467469+00:00.