Discover 7 completely free prepper calculators: Bug Out Bag Weight Calculator, Solar Power Calculator, Water Storage Calculator, Food Storage Calculator, 72-Hour Kit Builder, SHTF Simulator, and Readiness Quiz. No sign-up, no BS, just tools that help you prep smarter.
Look, I’ve spent way too many nights hunched over Excel trying to calculate whether my bug-out bag will actually break my back, or if I’ve bought enough rice to feed my family for three months without turning into carb zombies.
Spreadsheets are great if you’re an accountant. For the rest of us trying to prep without losing our minds? They’re torture.
So we did something about it.
Over the past few months, we’ve built 7 free interactive tools that do the math for you. No spreadsheets. No email gates. No “sign up for our course” BS. Just honest, field-tested calculators that actually help you prep smarter.
And yeah, they’re 100% free. Because the prepper community deserves better than another $97 course promising secrets the government doesn’t want you to know.
Here’s the truth: most prepping advice is either too vague (“store some food”) or so complex you need a PhD to understand it.
We wanted tools that:
So we built them. Tested them in the field. Fixed what broke. And now we’re handing them to you.
No catch. No upsell hiding at the end. Just good tools for good people trying to be ready.
All 7 tools live here: prepperevolution.com/tools
Ever loaded up your bug-out bag, lifted it, and thought “there’s no way I’m carrying this for 20 miles”?
Yeah. Same.
This tool fixes that. Pick from 40+ real gear items (shelter, water filtration, first aid, fire starting, food, etc.), and it tracks your total weight against your body weight. The rule of thumb: your BOB shouldn’t exceed 20-25% of your body weight for sustained carry.
What it does:
Who it’s for: Anyone building their first BOB, or anyone who’s been carrying a 60-pound death trap and wondering why their back hurts.
Real talk: I used this to cut 15 pounds from my own bag. Turns out I didn’t need three knives and a hatchet. (Okay, I still carry two knives. Don’t judge.)
Looking for a tested bug-out bag? Check our complete bug-out bag comparison guide.
Portable power stations are the best prep gear you can buy. But which size do you actually need? And how much solar do you need to keep it charged?
This tool does the math in 60 seconds.
How it works:
What it tells you:
Who it’s for: Overlanders planning off-grid trips, preppers building home backup systems, van lifers who are tired of guessing.
Pro tip: Use this before you drop $1,500 on a power station. You might only need a $900 unit. Or you might need way more capacity than you thought.
Need help choosing a power station? Our portable power station buyer’s guide breaks down the top models.
Either way, you’ll know.
FEMA says one gallon per person per day. But that’s for drinking only, assumes mild weather, and doesn’t account for cooking, hygiene, or medical needs.
We built a calculator that actually factors in reality.
What it considers:
What it tells you:
Who it’s for: Anyone who wants to stop guessing about water storage. (Spoiler: you probably need more than you think.)
Reality check: A family of 4 in a hot climate needs about 8-10 gallons per day for drinking, cooking, and basic hygiene. For 30 days, that’s 240-300 gallons.
Don’t forget filtration: See our best water filters for preppers or read our Sawyer Squeeze deep review.
Stack those 5-gallon jugs and see how fast your garage fills up.
Rice and beans will keep you alive. But you’ll hate life after two weeks.
This tool helps you plan a balanced food storage system based on calories, macros (protein/carbs/fat), and shelf life.
How it works:
What it tells you:
Who it’s for: Anyone building long-term food storage who’s tired of vague advice like “buy some canned goods.”
Pro tip: Most people under-estimate fat calories. Your body needs fat to function. Stock peanut butter, cooking oil, nuts, and canned fish. Your brain will thank you.
72-hour kits are different from bug-out bags. They’re for sheltering at home or evacuating by car-not hiking 20 miles through the woods.
This tool builds a personalized checklist based on YOUR situation.
What it asks:
What it gives you:
Who it’s for: Beginners building their first 72-hour kit, or experienced preppers who want to double-check they didn’t forget anything.
Reality check: Most pre-made 72-hour kits suck. They’re generic, overpriced, and missing half the stuff you actually need. Build your own with this tool, buy quality gear, save money.
This one’s different. It’s not a calculator-it’s a choose-your-own-adventure survival game.
You face realistic emergency scenarios (wildfire evacuation, grid-down winter storm, civil unrest, etc.) and make decisions. Your choices determine whether you make it out, and what gear would have saved you.
How it works:
Why it’s valuable:
Who it’s for: Anyone who wants to mentally rehearse emergencies without actually living through them. (Trust me, you want the practice.)
Fair warning: You’re going to fail some scenarios. That’s the point. Learn from the mistakes in the simulator so you don’t make them when it’s real.
Think you’re ready? Prove it.
This 10-question quiz tests your preparedness across water, food, power, shelter, medical, security, and skills. Takes 2 minutes. Results are shareable (so you can flex on your friends or roast them for being unprepared).
What it covers:
What you get:
Who it’s for: Anyone who wants an honest assessment of their prep level. (Hint: most people score 40-60. If you’re above 70, you’re doing better than 90% of people.)
Pro tip: Take the quiz, identify your weak spots, use the other tools to fix them. Retake the quiz in 3 months and watch your score climb.
Here’s the progression most people follow:
All tools save your data in your browser’s localStorage. That means:
You can print your checklists, screenshot your results, or share links with friends. But your actual data? That’s yours.
Because honestly, we don’t need to know how many freeze-dried meals you’re hoarding. That’s between you and your basement.
Look, we love spreadsheets. They’re great for tracking expenses and calculating mortgage payments.
But for prepping? They suck. Here’s why these tools win:
Bottom line: If you want to spend 12 hours watching someone ramble about preparedness philosophy, buy a course. If you want actual numbers you can use today, use our tools.
We’re not done. Here’s what we’re building next:
If there’s a tool you want us to build, let us know. We’re listening.
Here’s the truth: most people will read this, think “cool,” and never actually use the tools.
Don’t be most people.
Take 10 minutes right now and run through the Readiness Quiz. Or build your 72-hour kit. Or calculate your water storage. Pick one tool, use it, and you’ll be more prepared than you were 10 minutes ago.
Then share the tools with your crew. Your overlanding buddies. Your prepper friends. Your family members who keep saying “I should probably get ready but I don’t know where to start.”
Send them here: prepperevolution.com/tools
Because the best prep you can make is helping the people around you get ready too.
These tools were built by a family of five from New Jersey that actually preps. I am a mutual aid electrical worker who responds to storms across the country and a dad who has been camping and building overland rigs for years. Every tool on this page solves a problem I personally ran into: I could not find a bug-out bag calculator that used real weights, a water storage tool that accounted for apartments, or a solar calculator that factored in my ZIP code climate. So we built them. No accounts, no data collection, no paywalls.
Yes. No account required, no email gate, no premium tier. Every tool is free to use in your browser. Your data stays on your device and is never sent to our servers.
No. Open the tool, use it, and close it. Your data saves locally to your browser so you can come back later, but there is no login and we do not track what you enter.
Yes. All tools are responsive and work on mobile browsers. You can also install the site as a progressive web app (PWA) for offline access on most phones.
We use real product weights, actual FEMA guidelines, and verified vehicle specs. The bug-out bag calculator uses actual gear weights from manufacturer specs. The water calculator uses FEMA and Red Cross storage recommendations. The solar calculator uses NREL solar irradiance data for your ZIP code.
Yes. We are actively building new Ops Deck tools including a Fuel and Range Planner, Overland Load Balancer, Skills Gap Analyzer, and Threat-Specific Risk Dashboard. Check back regularly or follow us for updates.
We built these tools because we were tired of guessing. Tired of spreadsheets that broke. Tired of vague advice that didn’t translate into action.
We wanted calculators that actually help-that give you real numbers, personalized checklists, and honest recommendations based on field-tested knowledge.
So we built them. Tested them. Fixed what sucked. And now they’re yours.
No email required. No upsells. No tricks.
Just good tools for good people trying to be ready.
Get started: prepperevolution.com/tools
Stay prepared,
Mike + The Prepper Evolution Team
P.S. – If these tools save you even one bad gear purchase or one planning mistake, they’ve already paid for themselves. (And they’re free, so technically infinite ROI.)