Built for engineers

Unit conversion,
engineered right.

Fast, precise conversion for length, mass, pressure, energy and temperature. Exact SI constants, two-way editing, and it all runs right in your browser.

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Converter

Type in either field. Both sides update instantly.

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    Engineer’s cheat sheet

    The conversions you reach for every day.

    Made for the workbench

    Small tool, serious accuracy.

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    Instant, two-way

    Edit either side and watch the other update as you type. Swap units with one click.

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    Exact constants

    Built on defined SI values: the international inch and pound, standard atmosphere, thermochemical calorie.

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    Private & offline

    Every calculation happens in your browser. No sign-up, no tracking, no server round-trips.

    Simple pricing

    Free for students. Forever.

    Student

    $0 / forever
    • All 5 converters
    • 6 significant digits
    • Works offline in your browser
    • Light & dark mode
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    Pro

    $4 / month
    • Everything in Student
    • 15-digit extended precision
    • Saved conversion history
    • No ads, ever
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