PrepHow long would your food and water last?
Add what's in your pantry. You'll see how many days your household would last, what's holding you back, and what to buy next. Nothing leaves this browser.
Who's at home?
Saved in this browser for the other tools.
What have you got?
Add a date to leave out anything that's expired.
Water
Cans
Dry food
Jars, snacks and drinks
Add your own
From preppantry.app. Checked 2 November 2026. Independent tool, not official advice.
How it works
We add up the calories and water in what you enter, then divide by what your household needs in a day. Your days ready is the lower of food and water, because you can't make up for one with the other.
Each adult is counted at 2,000 kcal and 3 liters a day (about 0.8 gallons), each child at 1,600 kcal and 2 liters, and each pet at 1 liter. These are planning figures, the same ones the Prep app starts with, and they aren't personal advice. Ready.gov and the CDC suggest at least a gallon per person per day, which covers sanitation too, so you may want more water than this shows.
Anything past its date counts for nothing, so old stock can't flatter your total. That's cautious: many dates are about quality, not safety.
Example: two adults need 4,000 kcal and about 1.6 gallons a day. Six gallon jugs last about 3.8 days. Ten cans of baked beans is 4,260 kcal, a little over a day. Their days ready is 1, limited by food.
Common questions
How many days of supplies should I keep?
The CDC says at least 3 days of water, and 2 weeks if you can. Ready.gov says several days. Many households start with 3 days and build up to 2 weeks.
Why doesn't my stock count if it's past its date?
We leave expired items out so the total isn't flattering. Many dates are about quality rather than safety, so check before throwing good food away.
Do you save what I enter?
Only in this browser, so the other tools can use your household. Nothing is sent to us, and you can clear it at any time.
Is the calorie figure for each can exact?
No. We use typical pack sizes and USDA figures per 100 g, so treat the answer as a good estimate. Check the label if you want to be precise, and add a custom item.
Sources
- CDC: creating an emergency water supply
- Ready.gov: water
- USDA FoodData Central (energy per 100 g)
Checked on 2 November 2026. This is an independent tool and not official advice. See sources and method.