# Guesstimate: calculator — Uncertainty Calculator

> Uncertainty Calculator (iPhone/iPad app by mark cotton.)

- Source: https://appshunter.io/ios/app/guesstimate-calculator/id6761731404 (this page in markdown: same URL + `.md`)
- Developer: [mark cotton](https://appshunter.io/developer/1691976609)
- Category: Utilities, Reference
- Price: $2.99
- Age rating: 4+
- Requires: iOS 18.6 · 3 MB
- Languages: American English
- Released: 2026-04-08
- Data updated: 2026-07-22
- User reviews in markdown: https://appshunter.io/ios/app/guesstimate-calculator/id6761731404/reviews.md

## What is Guesstimate?

Ever wonder "what's the answer if this number could be anywhere from 2 to 4?" Guesstimate is a calculator built for uncertainty.

Use the ~ operator to define ranges in your formulas. For example, (2~4) * (1~3) means "a number between 2 and 4, multiplied by a number between 1 and 3." Guesstimate runs hundreds of thousands of Monte Carlo simulations to show you the full distribution of possible results.

FEATURES

- Uncertainty ranges: Use ~ to express "somewhere between" in any formula
- Monte Carlo simulation: Up to 10 million iterations for accurate results
- Interactive histogram: Tap bars to see exact percentages and sample counts
- Box plot visualization: See min, Q1, median, Q3, and max at a glance
- Full statistics: Mean, median, standard deviation, confidence intervals, and percentiles (P1 through P99)
- Calculation history: Review and reload past formulas
- Configurable settings: Adjust iteration count, histogram bins, confidence level, and distribution type (uniform or normal)
- Built-in calculator keypad: No keyboard needed — dedicated buttons for digits, operators, parentheses, and the ~ range operator
- Works on iPhone and iPad

EXAMPLES

- How much will dinner cost? (12~18) + (8~14) + (3~7)
- Estimating project hours? (2~4) * (5~8)
- Unit conversion with uncertainty? (2.79~3.09) * ((1300~1400) / (27~33))

No account required. No data collected. Just math.


## Version history (last 5 releases)

### 1.6 — 2026-07-11

Fable bug fixes

### 1.5 — 2026-04-18

New app icon!

### 1.4 — 2026-04-16

Voice input is not enabled by default for compatible devices.  Keyboard has additional functions like square root and exponents.

### 1.3 — 2026-04-11

On iOS 26 and later, use Voice Input to speak your formula in plain English — powered by on-device AI.

### 1.1 — 2026-04-08

Added haptic feedback on button presses

## More apps by mark cotton

- [Antisocial Feed](https://appshunter.io/ios/app/antisocial-feed/id6762880659)

All apps by mark cotton: https://appshunter.io/developer/1691976609

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-07-22.*