Calculators

Calculators you can run with your own numbers. Everything is calculated in your browser; nothing is sent anywhere. Each calculator states its assumptions and sources.

Home preparedness checklist: monthly, twice a year and yearly (printable)

2026-11-01 Calculators

A printable checklist for keeping your home ready: test smoke alarms monthly, practice your escape plan twice a year, replace stored water every 6 months, check CO detectors, extinguishers, fuel, furniture straps and your kit every year. Each item links to the article with its source. Nothing you check is saved or sent.

Hiking water calculator: body weight × hours × 5

2026-11-01 Calculators

How much water to drink on a hike, from a simple formula published by Japan's Hokkaido Government: water (ml) = body weight (kg) × hours of activity × 5. Enter pounds or kilograms. With a worked-examples table; everything is calculated in your browser.

Emergency toilet bag calculator (people × uses per day × days)

2026-11-01 Calculators

How many emergency toilet bags and toilet paper rolls to keep, using Japan's government guideline of 5 to 6 uses per person per day for 7 days. With a worked-examples table. Everything is calculated in your browser.

Printable go-bag checklist (Ready.gov list plus what Japan adds)

2026-11-01 Calculators

An interactive, printable emergency kit checklist: Ready.gov's basic kit and suggested additions, plus items Japan's government checklist adds, such as helmets, slip-on shoes and elder-care supplies. Nothing you check is saved or sent.

Household water and food calculator (U.S. and Japanese guidance)

2026-11-01 Calculators

How much water to store for your household, by U.S. guidance (one gallon per person per day) and Japanese guidance (3 liters per person per day), plus the number of meals. Runs in your browser.

Growing some of your own food: containers, community gardens and soil safety

Starting with containers (sun, drainage, potting mix, watering), community gardens and Japan's citizen farms, testing garden soil for lead and EPA's advice by lead level, and not planting toxic look-alikes such as daffodils next to chives.

Cooking for a crowd: planning and food safety for big batches

USDA's volunteer guide to cooking for groups, the current safe minimum temperatures, the 2-hour and 1-hour rules, cooling, reheating and transport, plus Japanese disaster-cooking numbers for how much rice to cook and what not to serve.

Choosing a campsite: flash floods, dead branches, wind and rockfall

Where to pitch and where not to, from the National Park Service, NOAA and Japan's river authorities: dry washes and sandbars, hazard trees, rockfall, wind and lightning, a five-direction check, the three knots for pitching, and drying your tent before storage.

Sleeping warm: sleeping bag temperature ratings and sleeping pad R-values

What the comfort, limit and extreme ratings on a sleeping bag mean (ISO 23537-1), how pad R-values are tested (ASTM F3340) and why stacked pads add up, how altitude lowers the temperature, Japan's shelter bed lessons, and avoiding low-temperature burns.

Disaster camping: Japan's habit of practicing a night without power, water or gas

Japanese schools and families practice for disasters by spending a night on camping gear and stored supplies. What those programs do, how the idea fits Ready.gov and Red Cross advice, how to start with a few hours, a one-night checklist, and the safety rules.