unsure

A calculator for things you're not sure about. Put a range where you'd guess a number, and see how the answer spreads out.

Try

History

    Calculations you finish with = show up here.

    How it works

    Write a calculation the usual way, but wherever you're unsure of a number, give a range. The calculator plays it out 100,000 times, each time picking a value from every range, and shows you how the answers spread out.

    Ranges

    10~20Anywhere from 10 to 20, all equally likely
    10~~20Bell curve: usually near 15, 95% of the time between 10 and 20
    10<~20Usually close to 10, occasionally up to 20
    10~>20Usually close to 20, occasionally down to 10
    5~~15|30~~45Either one or the other, equally likely. | binds tighter than × and +

    Times and durations

    17:30, 5:30pm and 5pm are times of day. 15m, 1h, 2h30m and 1.5h are durations. In a calculation with times, a plain number counts as minutes. A result past midnight shows (+1d).

    If there's a time of day anywhere in the calculation, the answer is a time; if there are only durations, it's a duration.

    Reading the result

    The big number is the median: half the outcomes land on each side of it. The 90% range leaves out the most extreme 5% at each end. In the histogram each bar is one slice of outcomes; above and below hold the outer 2% at each end. Tap a bar to see its odds.

    Hold × for ^ (power). Hold ⌫ to clear.

    Examples

    Based on Filip Hráček's Unsure Calculator (MIT), with times, durations and shaped ranges added. Source.

    Settings

    Clock