Prep Answers — Common Preparedness Q&A

Short answers from the same calculator math as the tools. Water, food, solar, and bug-out bag weight.

How much water does a family of 4 need for 2 weeks?

56 gallons at the FEMA floor. 112 gallons at 2 gallons per person per day.

How much water does a family of 4 need for 1 month?

120 gallons at the FEMA floor. 240 gallons at 2 gallons per person per day.

How much water should an apartment dweller store for 2 weeks?

20–30 gallons in stackable jugs + a WaterBOB for the tub.

How much food does a family of 4 need for 3 months?

About 720,000 calories — around 420 lbs of mixed shelf-stable food.

How much food does 1 person need for 1 year?

About 730,000 calories. 530 lbs in the staple list below.

How much food does a family of 2 need for 72 hours?

12,000 calories — about 6–8 lbs of food.

How many solar panels do I need for an apartment?

1–2 panels (100–200W total). A balcony setup maxes at about 200W.

How many solar panels do I need to run a house during an outage?

400–600W of panels paired with 2,000–4,000Wh of battery storage.

How many solar panels do I need for overlanding?

200–400W — two 100W portable panels or one 200W rigid panel.

How heavy should a bug out bag be for a 150 lb person?

30 lbs is 20% of 150 lbs. The calculator warns at 25% (37.5 lbs). That 25% line is unsourced.

How heavy should a bug out bag be for a 200 lb person?

40 lbs is 20% of 200 lbs. The calculator warns at 25% (50 lbs). That 25% line is unsourced.

What are the essential items in a bug out bag?

10 categories: water, food, shelter, fire, navigation, first aid, tools, comms, documents, clothing.

Bug-out bag calculator

Water storage calculator