Get the correct adjusted processing time or pressure for your elevation. Enter your altitude and canning method to see the exact USDA-recommended adjustment — whether you're water bath canning tomatoes or pressure canning green beans in Denver, Salt Lake City, or anywhere above sea level.
Not sure of your altitude? Search "elevation of [your city]" on Google, or use whatismyelevation.com. You can also check Google Maps — right-click your location and the first item is your elevation.
Use the processing time from your tested recipe (Ball Blue Book, USDA, National Center for Home Food Preservation) for 0–1,000 ft. Do not use untested recipes.
| Altitude (feet) | Add to Processing Time | Example: 20-min Recipe Becomes |
|---|---|---|
| 0 – 1,000 ft | No change | 20 min |
| 1,001 – 3,000 ft | +5 min | 25 min |
| 3,001 – 6,000 ft | +10 min | 30 min |
| 6,001 – 8,000 ft | +15 min | 35 min |
| 8,001 – 10,000 ft | +20 min | 40 min |
| Altitude (feet) | Dial Gauge Pressure |
|---|---|
| 0 – 2,000 ft | 11 lbs PSI |
| 2,001 – 4,000 ft | 12 lbs PSI |
| 4,001 – 6,000 ft | 13 lbs PSI |
| 6,001 – 8,000 ft | 14 lbs PSI |
| Above 8,000 ft | Consult local extension office |
| Altitude (feet) | Weighted Gauge Setting |
|---|---|
| 0 – 1,000 ft | 10 lbs weight |
| 1,001 ft and above | 15 lbs weight |
Click a city to auto-fill your altitude above.
Note: City buttons shown above are consolidated. Use the correctly labeled elevation button for your city.
| City | Elevation | WB Adjustment | Pressure (Dial) | Pressure (Weighted) |
|---|
This is not a minor technicality. At higher elevations, water boils at a lower temperature — and that reduced temperature is the exact mechanism that makes canning dangerous if you don't adjust.
At sea level, water boils at 212°F (100°C). In Denver at 5,280 feet, water boils at only about 202°F (94°C). That 10-degree difference sounds small, but the target temperature for destroying Clostridium botulinum spores in low-acid foods is 240°F — achievable only under pressure. In water bath canning of high-acid foods, you rely on boiling temperature and sustained processing time together to achieve safety. If your water is boiling at 202°F instead of 212°F, the same processing time does significantly less pathogen destruction work.
The danger is botulism. Clostridium botulinum produces one of the most potent toxins known. It thrives in anaerobic (oxygen-free), low-acid environments — exactly what a sealed canning jar creates. Botulism toxin is colorless, odorless, and tasteless; you cannot tell by looking at or smelling food whether it is contaminated. Under-processed jars can look perfectly normal and still be lethal.
Always use recipes from tested sources: the USDA Complete Guide to Home Canning, the Ball Blue Book, or the National Center for Home Food Preservation (nchfp.uga.edu). Old family recipes, Pinterest recipes, and social media recipes have not been scientifically tested for safe processing times and should not be used.
Yes — and it's one of the most overlooked safety factors in home canning. Water boils at a lower temperature the higher you go above sea level. At sea level, water boils at 212°F. At 5,000 feet, it boils at about 203°F. At 7,500 feet, it's around 198°F. Water bath canning relies on sustained boiling to achieve the internal temperature and time needed to destroy molds, yeasts, and pathogens in high-acid foods. When your boiling point is lower, the same recipe processing time doesn't deliver the same safety margin. The USDA compensates for this by adding extra minutes to processing time at each elevation band. If you live above 1,000 feet and you've been using sea-level processing times, your canned food may be under-processed — even if it sealed correctly and looks fine.
The fastest method: search "elevation of [your city or address]" in Google. The search result usually shows your elevation at the top. For a more precise reading, visit whatismyelevation.com and allow location access — it will show your exact GPS-determined elevation. You can also open Google Maps, right-click on your exact property location, and the first line of the popup shows your coordinates and elevation. If you live in a hilly area, the elevation of the center of your city may differ meaningfully from your actual homestead — use GPS or a map-based tool to get your specific location's reading rather than a city average. For serious canners in hilly or mountainous terrain, a difference of 500 feet in either direction can shift you into a different adjustment category.
In water bath canning, under-processing due to altitude failure means your food did not reach the temperature-time combination needed to destroy pathogens and spoilage organisms. The jar may seal perfectly — lids ping, pass the vacuum test, look airtight — and still contain viable botulism spores. Botulism toxin has no color, no odor, and no taste. You cannot detect it without laboratory testing. Consuming under-processed food containing botulism toxin causes botulism poisoning, which is potentially fatal and requires intensive medical care including mechanical ventilation. Even if the risk in any single jar is low, the consequence of the failure is severe enough that proper altitude adjustment is treated as a non-negotiable food safety requirement by every major canning authority. In pressure canning, altitude failure means you likely aren't actually reaching 240°F inside the canner — the temperature required to destroy botulism spores in low-acid foods. Increasing the pressure setting compensates for the lower ambient pressure at elevation, ensuring the canner reaches the correct internal temperature.
Pressure canning achieves a much higher internal temperature (240°F vs. 212°F maximum for water bath), which is why it is required for all low-acid foods — meats, fish, most vegetables, beans, soups. For those foods, water bath canning is not safe at any altitude; it simply cannot reach the temperature needed to destroy botulism spores. However, for high-acid foods (most fruits, pickles, jams with proper acid levels, tomatoes with added acid), water bath canning done correctly at the right altitude adjustment is completely safe. "Safer" depends on the food type: for low-acid foods, pressure canning is the only safe option. For high-acid foods, both methods are safe when proper altitude adjustments and tested recipes are used. Pressure canning high-acid foods is not unsafe — it's just unnecessary, and the extra heat can reduce quality and texture of delicate fruits and jams. Use the method appropriate to your food's acid level, always from a tested recipe.
No — with pressure canning, the adjustment is in pressure, not time. The processing times in pressure canning recipes are calibrated assuming you will reach 240°F inside the canner. If you increase the pressure to compensate for altitude, you maintain that 240°F target, and the processing time stays the same. If you were to instead try to add more time without increasing pressure, you'd still never reach 240°F at altitude — the extra time wouldn't compensate for the lower temperature. This is the opposite of water bath canning, where time is the variable you adjust. For pressure canning: adjust pressure up, keep time the same. For water bath canning: adjust time up, temperature is fixed by boiling point.
Weighted gauges (the kind with a weight that rocks or jiggles) do not drift out of calibration the way dial gauges do. They work by allowing steam to escape when pressure exceeds the weight's set point — mechanically simple and inherently self-regulating. The tradeoff is that you have only two settings (10 lbs and 15 lbs on most models), which is why the weighted gauge altitude adjustment is a simple binary: use 10 lbs below 1,000 ft, and 15 lbs at 1,001 ft and above. Dial gauges can read inaccurately over time and should be tested annually at your local cooperative extension office (usually free). If your dial gauge reads high by even 1 lb, your actual pressure may be lower than you think — meaning lower temperature and less pathogen destruction than required. Always have dial gauges tested before each canning season if they're more than a year old.