Unsure Calculator

Calculate With Numbers You Are Not Sure About

A normal calculator asks you to pretend every input is exact. This one lets you keep the uncertainty in the formula. When you write 10~15, read it as “ten to fifteen”: a range you are roughly 95% confident contains the real value.

The result is also a range. For example, the default budget-style formula estimates a likely low and high outcome instead of a single fragile number. The histogram shows where outcomes tend to cluster, and the percentiles show how much risk sits in the tails.

Notation

Examples: 10~15, (1000~1500) * (30~50 / 100), 100 x tan(70~80).

• ~ means an uncertain range, modeled as a normal distribution.
• ^ means exponentiation, so 2^3 is eight.
• sqrt, sin, cos, and tan are supported. Trig functions use degrees.

Limitations

Notes: ranges are interpreted as normal distributions where the low/high values are two standard deviations from the mean (roughly 95% interval). This is for back-of-the-napkin reasoning, not strict statistical modeling.