How it works

You give us a recipe and three facts about your kitchen: your altitude, anything you're short on, and anything you're out of. We read the recipe, you check it, and fixed published rules do the rest. No guessing and no AI math.

Read. Pasted text is read in your browser. For a link, our server reads the page's structured recipe data (schema.org), keeps only the ingredient list, oven temperature, time, yield and recipe type, and links you back for the method. The steps we show for a link are general steps for that kind of recipe, written by us. For a photo, text recognition runs on your device (Tesseract), so your photo never leaves your phone.
One click, then check. You get the finished recipe right away. If we couldn't read an amount we say so, and "Edit ingredients" lets you fix any line or step and see the result update instantly. Text recognition and web pages both make mistakes, especially with handwriting.
Scale. Short on something ("only 2 eggs")? We work out the batch size that uses exactly what you have, then scale every line and round to amounts you can measure (eggs to halves, spoons to eighths, cups to quarters and thirds). If the altitude rules add flour or liquid you're short on, we shrink the batch a little more so it still fits.
Where was it written? We work out the altitude the recipe was written for (usually sea level) and show you why, so you can change it with one tap. If that's close to your altitude, we tell you no adjustment is needed.
Adjust. We apply the altitude rules below for your kind of recipe and show the reason and source on every changed line.
Swap. Out of something? We size a tested substitute from CSU Extension's substitution table to the amount your recipe needs.

CSU Extension's own advice: "Do not assume that your sea level recipe will fail. Try it first." And try the smaller adjustment first. That's why Light touch is the default and Full is one tap away.

Finding your altitude

ZIP codes are matched to a town location from GeoNames (CC BY 4.0), with US Census ZCTA centroids as a backup. Elevations were precomputed from the Copernicus GLO-90 digital elevation model via the Open-Meteo Elevation API and bundled with the site, so no lookup service is called when you type a ZIP. Mountain ZIP codes can span thousands of feet; if you know your own altitude, switch to Feet.

Cakes, cake-like quick breads and muffins

From CSU Extension's Table 3 (Colorado State University Extension, High Elevation Food Preparation Guide (reviewed Oct 2025)). Light touch uses the smaller number in each range, Full uses the larger.

Adjustment	3,500–6,500 ft	6,500–8,500 ft	8,500–10,000 ft
Reduce baking powder/soda, for each tsp	⅛ tsp	⅛–¼ tsp	¼ tsp
Reduce sugar, for each cup	0–1 Tbsp	0–2 Tbsp	1–3 Tbsp
Add liquid, for each cup	1–2 Tbsp	2–4 Tbsp	3–4 Tbsp

CSU's table starts at 3,500 ft and King Arthur's guidance at 3,000 ft. Between 3,000 and 3,500 ft we use the first column. Above 10,000 ft we use the last column and warn you that you're past the published tables.

Leaveners: King Arthur's chart (used in Full mode)

From King Arthur Baking, High-Altitude Baking guide. Amounts between rows are interpolated; above 8,000 ft we use the highest band and say so. King Arthur's numbers cut leavener more than CSU's, which is why they're the "Full" option.

Recipe calls for	3,000–5,000 ft	5,000–6,500 ft	6,500–8,000 ft
1 tsp	⅞ tsp	½ tsp	¼ tsp
1½ tsp	1¼ tsp	¾ tsp	½ tsp
2 tsp	1½ tsp	1 tsp	¾ tsp
2½ tsp	1¾ tsp	1¼ tsp	1 tsp
3 tsp	2 tsp	1¼ tsp	1 tsp
3½ tsp	2½ tsp	1½ tsp	1 tsp
4 tsp	2½ tsp	1½ tsp	1 tsp

Everything else

Rule	Applies to	Light touch	Full	Source
Oven temperature	Cakes, quick breads, muffins, cookies, brownies, biscuits	+15°F	+25°F (always +15°F for chocolate cakes)	King Arthur; CSU (15–25°F)
Bake time	Same	5 min less per 30 min (cookies: 1 per 10)	8 min less per 30 min (cookies: 2 per 10)	King Arthur
Flour	Cakes, quick breads, muffins, cookies, brownies	+1 Tbsp at 3,500 ft, +1 Tbsp more per extra 1,500 ft		King Arthur
Sugar (cookies, brownies)	Cookies, brownies	No change	1 Tbsp less per cup	King Arthur
Liquid (cookies, brownies)	Cookies, brownies	+1 Tbsp at 3,000 ft	+2 Tbsp at 3,000 ft	King Arthur (+1½ tsp per extra 1,000 ft, both modes)
Yeast	Yeast breads, rolls, pizza	About 10% less (¼ tsp per 2½ tsp packet)	25% less	CSU (bread machines); King Arthur
Biscuits, scones, pancakes		Leavener only, per CSU Table 3		CSU
Frying oil	Doughnuts, fritters	About 3°F lower per 1,000 ft		CSU; King Arthur
Pie crust		No amount changes; tips only		King Arthur; CSU
Angel food, chiffon, sponge		Tips only. CSU gives no fixed amounts, so we don't invent any.		CSU; King Arthur
Frostings, glazes, fillings		Scaled only

What altitude was the recipe written for?

Every recipe starts with a "written for" altitude. Most published recipes are written at or near sea level, so that's the default. We change it only when there's evidence, in this order, and we show the reason with your result, where you can change it in one tap:

The recipe says so. Phrases like "adjusted for 5,000 feet", "high altitude (7,000 ft)", "tested at 8,750'", "I live at 6,200 ft" or "1,600 m above sea level". Advice for other bakers ("if you live above 3,500 ft…") doesn't count. If a recipe gives several different altitudes, we ask you to pick.
A site we know. A short list of sites that state where their recipes are tested (checked by hand, October 2026):
- kingarthurbaking.com (high-altitude recipe pages only): 5,000 ft. King Arthur's high-altitude recipes are developed and tested at 5,000 ft.
- extension.colostate.edu: about 5,000 ft. CSU Extension publishes high-altitude recipes for Colorado (3,500–10,000 ft); we assume about 5,000 ft unless the page says.
- curlygirlkitchen.com: 5,280 ft. Recipes are tested in Colorado at 5,280 ft for high-altitude bakers.
- alpinespoon.com: 8,000 ft. Recipes are developed at 8,000 ft.
- mountainsidebakery.com: 8,600 ft. Recipes are baked at about 8,600 ft in Colorado.
- highaltitudebaker.com: 8,750 ft. Recipes are baked in Telluride, Colorado, at 8,750 ft.
- highaltitudebaking.com: you pick. Recipes list separate amounts for several altitudes, so pick the column you copied.
A home town. "Here in Denver", "my kitchen in Santa Fe" or "Boulder, CO" use that town's approximate elevation. A dish name like "Denver omelet" doesn't count, and a state name alone is marked as a rough guess.
"High altitude" alone. A recipe titled or described as high-altitude with no number is assumed to be about 5,000 ft, the altitude King Arthur tests at. Please change it if you know better.

For links, we look only at the recipe's own title, description, keywords and steps, not the site's menus. You can always set it yourself: Sea level, Feet or ZIP.

When no adjustment is needed

If the recipe and your kitchen are both below 3,000 ft, or within about 1,000 ft of each other, we say No adjustment needed and leave the amounts, oven and time as written. Scaling ("only 2 eggs") and substitutions still work. Why 1,000 ft: CSU's table steps every 2,500 ft and King Arthur's every 1,500–2,000 ft, so a smaller gap is below what the published rules can resolve. CSU also says not to assume a recipe will fail: try it first.

Going up, and going down

Up (for example sea level → 5,500 ft, or 5,000 → 8,000 ft). The published rules are written for sea-level recipes. For a recipe already adjusted for some altitude, we first work out its sea-level version by reversing the rules for the altitude it was written for, then apply the rules for your altitude. Only the difference changes. Lines that come out the same (within a measuring-spoon rounding) are left as written. The oven and time are compared with what the recipe says.

Down (for example a 7,000 ft recipe → sea level). This is our best estimate: published guidance covers going up, not down. We reverse each rule. Leavener and sugar go back up (dividing by the same fractions CSU and King Arthur subtract; for King Arthur's chart we take the smallest sea-level amount that maps to the recipe's amount). Some of the added liquid comes out (always leaving at least a quarter of that liquid), and the added flour comes out. The oven comes down by the same 15–25°F but not below 350°F unless the recipe was already lower, and the time gets longer only if the oven came down. Yeast goes back up. Frying oil goes up about 3°F per 1,000 ft. Watch your first bake and check doneness early and late. Canning and candy stay blocked in both directions.

Sources for the reversed rules: the same CSU Table 3 and King Arthur chart above. King Arthur publishes high-altitude versions of some recipes, tested at 5,000 ft. Susan G. Purdy's Pie in the Sky lists each recipe at several altitudes. Neither gives rules for going down.

What we refuse to convert

Canning, jams, jellies and preserves, and candy or sugar-syrup temperatures. These are food-safety and burn-risk questions, not taste tweaks. We stop and point you to National Center for Home Food Preservation (USDA-funded), Selecting the correct processing time and Colorado State University Extension, High Elevation Food Preparation Guide (reviewed Oct 2025). We also never change meat or egg doneness temperatures.

Copyright and recipe sites

A list of ingredients is a set of facts. A recipe's directions, stories and photos belong to their author. So when you use a link, we show only the adjusted ingredient list, oven temperature, bake time, general steps for that type of recipe written in our own words, and our own short notes, and link to the original for the full method. We don't store or publish converted recipes.