Boiling point (°F) = 212 − (altitude in feet ÷ 544) (≈ −1 °F per 550 ft)
Boiling point (°C) = (°F − 32) × 5⁄9
Cook-time adjustment (above 3,000 ft):
extra minutes = per-food rate × (altitude − 3,000) ÷ 1,000
adjusted time = ⌈sea-level minutes + extra minutes⌉
At sea level, water boils at 212°F (100°C). Drive your rig up to a 10,000-foot campsite in the Rockies, and that same pot of water boils at roughly 194°F (90°C). The difference is immediately obvious when you try to cook pasta and it still feels crunchy after the usual eight minutes. The physics behind this is straightforward: boiling occurs when the vapor pressure of water equals the surrounding atmospheric pressure. At altitude, atmospheric pressure is lower, so water transitions to vapor at a lower temperature.
The key insight is that food cooks from the heat of the liquid, not from the act of boiling. A vigorously rolling boil at 10,000 feet is cooler than a bare simmer at sea level. The violent bubbling creates the illusion of high-temperature cooking, but your pasta is sitting in water that is 18°F cooler than at sea level, and it will take proportionally longer to cook through. The same applies to eggs, rice, lentils, and every other boiled food.
The 1°F Per 550-Foot Rule
Boiling point drops approximately 1°F for every 550 feet of altitude gain (about 1.8°F per 1,000 feet). This is a simplified rule that holds well in the altitude range most overlanders encounter: 3,000 to 14,000 feet. At 8,000 feet, the boiling point is roughly 197°F; at 12,000 feet, approximately 190°F. The effect on cooking becomes meaningful above 3,000 feet and grows significantly above 7,000 feet.
Pressure Cookers: The Best High-Altitude Solution
A pressure cooker solves the altitude cooking problem at its root. By sealing the cooking vessel and building internal pressure above atmospheric, a pressure cooker raises the boiling point inside the pot back toward or above sea-level temperatures, even at 12,000 feet. Meal times return close to normal, and you use less fuel because the cooking is faster and more efficient. For overlanders camping regularly above 7,000 feet, a camp pressure cooker is a worthwhile investment. At lower altitudes, adding extra cooking time is the simpler solution.
Planning for High-Altitude Camp Cooking
When planning meals for a high-altitude trip, estimate cooking times using the table in this calculator. Bring a reliable way to test doneness: a fork for pasta and potatoes, a thermometer for meat. Pre-soaking dried beans and lentils overnight dramatically reduces the time needed to cook them at altitude. Choose meals that are forgiving of extended cooking times over those that are timing-sensitive. Instant rice and couscous are better choices than traditional rice for high camps; instant oats over rolled oats. A camp thermometer can confirm your water temperature for critical recipes.
