ExactUnits
↑↓ move ↵ open Esc close All shortcuts

High-altitude baking adjustment calculator

Lower air pressure means gases expand more and water boils cooler, so cakes rise too fast and dry out. The standard corrections scale with altitude.

m
degrees C
Baking powder
8.50g
≈ Rounded High-altitude baking
Sugar
191.4
Liquid
250.3
Flour
256.4
Oven temperature
186 degrees C
Water boils at
94.1 degrees C
Air pressure
81 489 Pa
Altitude in feet
5906
Show the working
  1. Altitude = 1800
  2. Flour in the recipe = 250
  3. Sugar in the recipe = 200
  4. Liquid in the recipe = 240
  5. Baking powder = 10
  6. Recipe oven temperature = 180
  7. Altitude in feet = 1800 * 3.280839895013123 = 5905.51
  8. severity = clamp((1800 - 900) / 2100, 0, 1) = 0.428 571
  9. Air pressure = 101325 * (1 - 2.25577e-5 * 1800)^5.25588 = 81 489.2
  10. Water boils at = 100 - 1800 * 0.0033 = 94.06
  11. Baking powder = 10 * (1 - 0.35 * 0.428 571) = 8.5
  12. Sugar = 200 * (1 - 0.10 * 0.428 571) = 191.429
  13. Liquid = 240 * (1 + 0.10 * 0.428 571) = 250.286
  14. Flour = 250 * (1 + 0.06 * 0.428 571) = 256.429
  15. Oven temperature = 180 + 15 * 0.428 571 = 186.429

Values are shown to six significant figures here; the arithmetic itself runs on exact fractions and is only rounded where a number is printed.

Scenarios & local history

Compare a saved scenario

Recent calculations

    The formula

    • barometric formula: p = 101325 (1 - 2.25577e-5 h)^5.25588
    • boiling point falls roughly 1 degree Celsius per 300 m
    • corrections ramp in from about 900 m and reach full strength near 3000 m

    Below about 900 m no adjustment is needed. The ramp used here is a linear interpolation of the standard published guidance, not a physical law.

    Bread is far more forgiving than cake: shorten the rise rather than changing the formula.

    Related calculators

    Settings

    Theme

    System follows your operating system and changes with it.

    Text size
    High contrast

    Maximises text and border contrast and removes the grid background.

    Graph-paper background
    Round to
    Notation
    Thousands separators
    Decimal mark
    Nearest fraction

    Shows the result as the nearest tape-measure fraction, with the error it costs.

    Accessibility & interaction
    Reduce motion Stops interface animations even when the operating system does not.
    Underline links Keeps links visually distinct without relying on colour.
    Larger touch targets Makes buttons and form controls easier to tap.
    Shorter reading lines Limits article width for easier scanning.
    Monochrome display Removes colour as an information cue.
    Always-visible focus Makes the keyboard focus ring persistent and stronger.
    Verbose screen-reader results Announces the complete conversion equation.
    Sticky action bars Keeps converter and calculator actions within reach.
    Select values on focus Replaces a value immediately when you start typing.
    Left-handed mobile layout Moves key mobile actions toward the left thumb.
    Your data

    Settings, recent conversions and favourites live in this browser only. Nothing is sent anywhere.

    Offline library