Free tools

Free Outdoor Calculators

40 free, no-sign-up calculators for hiking, camping, fishing, hunting, cycling, climbing, paddling and life on the road. Pick one to get started.

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Hiking & Backpacking

Backpack Weight Work out your total loaded pack weight from base gear, food and water —… Open → Hiking Time Estimate how long a hike will take using Naismith’s rule — distance plus climbing… Open → Hiking Calories Estimate the calories you burn hiking based on your body weight, pack weight, time… Open → Trail Water Estimate how much water to carry on a hike based on time on trail,… Open → Pace & Distance Convert your hiking pace into total time and speed for any distance — plan… Open →
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Camping

Tent Size Find out what tent capacity and floor area you actually need for your group… Open → Sleeping Bag Rating Find the sleeping bag temperature rating you need for the overnight lows you expect,… Open → Campfire Wood Estimate how many bundles or logs of firewood you need for your camping trip… Open → Cooler Ice Estimate how much ice you need to keep a cooler cold for your trip,… Open → Stove Fuel Estimate how much stove fuel — canister or liquid — you need for a… Open →
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Fishing

Fish Weight Estimate a fish’s weight from its length and girth — perfect for catch-and-release records… Open → Fillet Yield Estimate how much boneless fillet you’ll get from a whole fish, and how many… Open → Line Capacity Work out how many yards of a new line will fit on your reel… Open → Trolling Depth Estimate how deep your trolled lure is running based on how much line you… Open →
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Hunting & Archery

Arrow KE & FOC Calculate your arrow’s kinetic energy, momentum and front-of-center (FOC) balance from arrow weight, speed… Open → MOA Adjustment Turn a miss distance at a known range into the exact MOA correction and… Open → Draw Length Estimate your archery draw length from your arm span — the key measurement for… Open → Venison Yield Estimate how much boneless venison you’ll get from a deer based on its live… Open →
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Cycling

Gear Inches Calculate gear inches, meters of development and speed at a given cadence from your… Open → Speed from Cadence Work out your bike speed from your gear and pedaling cadence — see how… Open → Cycling Calories Estimate the calories you burn cycling based on your body weight, ride time and… Open → Tire Pressure Get a recommended bike tire pressure based on your combined rider and bike weight… Open → Power-to-Weight Calculate your watts per kilogram (W/kg) from your FTP and body weight — the… Open →
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Climbing

Rope Length Work out what length of climbing rope you need for a route or rappel… Open → Fall Factor Calculate the fall factor of a climbing fall — the ratio of fall distance… Open → Grade Converter Convert rock climbing grades between the American YDS, French, UIAA and British systems in… Open → Rappel Distance Work out the maximum rappel distance you can safely descend on a given rope… Open →
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Kayak & Canoe

Kayak Paddle Length Find the right kayak paddle length for your height and your kayak’s width —… Open → Kayak Capacity Find your kayak’s usable weight capacity — not just the maker’s max — so… Open → Paddling Time Estimate how long a kayak or canoe trip will take from the distance, your… Open → Canoe Paddle Length Estimate the right canoe paddle length from your height so your top hand sits… Open →
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RV & Road Trip

RV Payload Work out your RV’s real cargo carrying capacity (CCC) and whether your passengers, water… Open → Tongue Weight Calculate the correct trailer tongue weight — 10 to 15% of loaded trailer weight… Open → Tank Duration Estimate how many days you can boondock before your fresh, grey or black tank… Open → Trip Fuel Cost Estimate the fuel cost of a road trip from the distance, your vehicle’s fuel… Open → Generator Size Work out what size generator you need to run your RV, including the big… Open →
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Weather & Safety

Wind Chill Calculate the wind chill “feels-like” temperature from the air temperature and wind speed, using… Open → Heat Index Calculate the heat index “feels-like” temperature from air temperature and humidity, and see the… Open → Dew Point Calculate the dew point from temperature and humidity to gauge how muggy it will… Open → Turnaround Time Work out your turnaround time on a hike so you get back to the… Open →

All tools give practical estimates — trails, gear, weather and conditions vary. Verify safety-critical figures (rope length, load limits, cold-weather ratings) against manufacturer specs and expert guidance.