What Size Generator Do I Need?
Select your appliances and get exact wattage requirements. Running watts, starting surge, and recommended generator sizes.
Calculate Generator Size
20+ Free Calculators
Emergency Preparedness Calculators
Stop guessing and start calculating. Get precise, actionable numbers based on official FEMA, CDC, and Red Cross guidelines. Your data stays in your browser.
MOST SEARCHED
Generator & Power Calculators
Our most popular tools. Answer the questions everyone asks during power outages.
How Long Will My Generator Last?
Enter fuel capacity and load to calculate runtime. Plan fuel storage for 3, 7, or 14-day power outages.
Calculate Generator RuntimePower Station Runtime Calculator
How long will your Jackery, Bluetti, or EcoFlow last? Calculate battery backup runtime for any device combination.
Calculate Battery RuntimePropane Tank Runtime Calculator
How long will a 20lb propane tank last? Calculate runtime for generators, heaters, stoves, and grills.
Calculate Propane RuntimeSolar Recharge Time Calculator
How long to charge your power station with solar? Calculate realistic charging times based on panel size and conditions.
Calculate Solar Charge TimeUPS / Battery Backup Sizing
What size UPS do you need for your computer? Calculate VA rating and runtime for home office and network equipment.
Size Your UPSPower Runtime Calculator
How long will your battery backup run your appliances? Calculate runtime with multiple devices and solar input.
Calculate Power RuntimeFuel Storage Calculator
How much fuel to store for emergencies? Calculate gasoline, diesel, or propane needs with safety guidelines.
Calculate Fuel Storage
ESSENTIALS
Water, Food & Supplies
The foundation of emergency preparedness. Calculate exactly what your household needs to survive.
Water Storage Calculator
Calculate gallons needed based on family size, climate, and duration. Water is your #1 survival priority.
Calculate Water NeedsFood Storage Calculator
Determine calories and pounds of food by category. Complete nutritional requirements for long-term storage.
Calculate Food NeedsEmergency Kit Calculator
Build a complete, prioritized supply checklist customized for your household and local disaster risks.
Build Kit ChecklistFirst Aid Kit Calculator
Build a comprehensive medical kit scaled to your family. Includes trauma options and expiration tracking.
Build First Aid KitWater Purification Calculator
Calculate purification supplies needed: bleach, tablets, or filter capacity for treating water sources.
Calculate PurificationSurvival Calorie Calculator
Calculate exact caloric needs during emergencies based on body composition, activity, and climate.
Calculate Calories
EVACUATION
Bug-Out & Mobility Calculators
When you need to move fast, know your limits and optimize your gear.
Bug-Out Bag Weight Calculator
Ensure your go-bag isn't too heavy. Calculate weight as percentage of body weight with optimization tips.
Optimize Pack WeightEvacuation Time Calculator
How long will it take your family to evacuate? Calculate realistic timelines based on preparedness level.
Calculate Evacuation TimeCommunication Range Calculator
What radio do you need? Calculate range requirements based on terrain and distance to family members.
Calculate Radio Range
SPECIALIZED
Pets, Medical & Budgeting
Address specific needs for your household's unique requirements.
Pet Emergency Supplies
Don't forget your furry family members. Calculate food, water, and supplies for dogs, cats, and more.
Calculate Pet SuppliesMedication Stockpile Calculator
Plan OTC and prescription medication supplies. Includes storage tips and expiration tracking.
Plan Medication SupplyEmergency Budget Calculator
Plan your preparedness spending. See cost breakdowns and prioritize purchases by importance.
Plan Your BudgetShelter Capacity Calculator
Determine how many people can shelter in your space and supplies needed for extended stays.
Calculate CapacityNot Sure Where to Start?
Start with the basics: water is your most critical survival resource, and power keeps your essentials running. Pick one and begin.