Calculate chemical dosages, equipment sizing, water volume, and operating costs for your pool or spa — all for free. No signup, no guesswork.
Pack weight, daylight hours, food planning, water carry, hiking time, and fuel calculators.
Map distance, declination, wind chill, heat index, lightning, elevation, and UV calculators.
Sleeping bag, tent, sleeping pad, rope, battery, water filter, and gear cost calculators.
Bear canister, hypothermia risk, dehydration, emergency shelter, and altitude calculators.
Calculate your total pack weight from individual gear items. Categorizes weight into base weight, consumables, and worn weight to help you go ultralight.
Calculate daily calorie needs and total food weight for backpacking trips. Accounts for activity level, body weight, and trip duration.
Estimate hiking duration using Naismith's Rule: 1 hour per 3 miles plus 1 hour per 2,000 feet of elevation gain. Accounts for terrain and pack weight.
Calculate the feels-like temperature from wind chill using the NWS formula. Critical for cold-weather camping safety.
Calculate the apparent temperature from heat and humidity using the NWS heat index formula. Know your heat stroke risk before hot-weather hiking.
Determine your sleeping bag comfort rating based on expected overnight lows, sleeping style, and pad R-value. Find the right bag for your conditions.
Calculate what tent capacity you need based on number of occupants, gear storage needs, and comfort preferences. Avoid cramped nights.
Calculate battery capacity needed for your devices over a multi-day trip. Covers phones, headlamps, GPS units, cameras, and other electronics.
Calculate the bear canister size needed based on trip duration, number of people, and food density. Required in many wilderness areas.
Assess hypothermia risk based on temperature, wind, wetness, and activity level. Understand the danger zone before it becomes an emergency.