Free tools

Free Backyard Calculators

40 free, no-sign-up calculators for grilling, pools, gardening, stargazing and every other corner of your backyard. Pick one to get started.

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Pool

Pool Volume Calculate how many gallons your swimming pool holds — for rectangle, round and oval… Open → Pool Salt Find out how many pounds of salt to add to your saltwater pool to… Open → Pool Shock Calculate how much liquid chlorine or cal-hypo shock to add to raise your pool’s… Open → Pool Heater Estimate the BTUs and hours needed to raise your pool temperature by a given… Open → Pool Alkalinity Calculate how much muriatic acid to add to lower your pool’s total alkalinity to… Open → Pump Run Time Calculate how long to run your pool pump each day for a full water… Open →
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BBQ, Grill & Smoking

BBQ Party Planner Work out how many burgers, hot dogs, buns, sides and drinks you need for… Open → Smoking Time Estimate how long to smoke pork butt, brisket, ribs, chicken and more at 225–250°F,… Open → Brine Calculator Calculate the salt and water for a wet brine using a 6% ratio, plus… Open → Pulled Pork Find out how much raw pork butt to buy for a crowd — accounting… Open → Charcoal Amount Estimate how many charcoal briquettes you need for your grill size and heat level. Open → Dry Rub Calculate how much dry rub to use for your cut of meat, using the… Open →
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Recipes & Cooking

Turkey Cooking Time Calculate how long to roast a turkey at 325°F by weight, for stuffed or… Open → Recipe Scaler Scale any recipe up or down by servings and instantly convert an ingredient amount… Open → Deep Fry Turkey Estimate the peanut oil and fry time for a deep-fried turkey by weight, with… Open → Ham Cooking Time Calculate how long to bake a ham at 325°F by weight, for pre-cooked (city)… Open → Prime Rib Time Estimate prime rib roast time at 325°F by weight and doneness, with the temperature… Open → Meat Thawing Calculate how long to safely thaw meat by weight in the refrigerator or in… Open →
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Gardening & Lawn

Mulch Calculate how many cubic yards or bags of mulch you need to cover a… Open → Raised Bed Soil Calculate how much soil (cubic feet, cubic yards or bags) it takes to fill… Open → Grass Seed Calculate how many pounds of grass seed you need for a new lawn or… Open → Fertilizer Calculate how much fertilizer to apply to deliver a target amount of nitrogen per… Open → Gravel Calculate the cubic yards and tons of gravel you need to cover an area… Open → Plant Spacing Calculate how many plants fit in a garden bed at a given spacing, for… Open → Sod Calculate how much sod you need in square feet, rolls and pallets to cover… Open →
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Animals & More

Chicken Coop Size Calculate the coop floor space, run size, nesting boxes and roost length you need… Open → Chicken Feed Estimate how much feed your flock eats per day, week and month, and how… Open → Egg Production Estimate how many eggs your flock will lay per week, month and year based… Open →
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Telescope

Telescope Magnification Calculate a telescope’s magnification from its focal length and eyepiece, including a Barlow lens. Open → Max Magnification Find your telescope’s maximum useful magnification from its aperture, plus a realistic limit for… Open → Field of View Calculate the true field of view of a telescope and eyepiece from the eyepiece’s… Open → Focal Ratio Calculate a telescope’s focal ratio (f-number) from its aperture and focal length, and see… Open → Resolving Power Calculate your telescope’s resolving power — the Dawes and Rayleigh limits in arc-seconds —… Open → Exit Pupil Calculate the exit pupil of a telescope and eyepiece from the aperture and magnification… Open →
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Trampoline

Trampoline Size Find the largest trampoline that safely fits your yard, including the recommended safety clearance… Open →
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Backyard & Outdoor

Concrete Slab Calculate the cubic yards of concrete and number of 60-lb or 80-lb bags needed… Open → Firewood Cord Measure a firewood stack and calculate what fraction of a full cord (or face… Open → Decking Boards Calculate how many deck boards and how much linear footage you need to cover… Open → Fence Materials Calculate posts, rails, pickets and concrete for a wood fence from its length, post… Open → Paver Patio Calculate how many pavers you need for a patio or walkway from the area… Open →

All tools give practical estimates — pools, grills, gardens and yards vary. Verify critical figures (like meat doneness) with a thermometer or a pro.