Free Shopping Tools & Calculators
Buying the wrong size is the most expensive mistake in home shopping — and the one a quick calculation prevents. Our free tools do the math for you, then show you the best-rated options in your exact size on Amazon.
Free tool
Rug Size Calculator
Enter your room dimensions and room type — get the standard rug sizes that will actually fit, with a visual layout diagram.
Calculate rug size → Free toolTV Size Calculator
Enter your viewing distance and resolution — get the ideal screen size range using the same rule home theater pros use.
Find your TV size → Free toolTV Wall Mount Finder
Enter your TV size and wall type — get the right VESA pattern and mount type (fixed, tilting, or full-motion).
Find your mount → Free toolSmart Lock Compatibility Checker
Answer three questions about your door — find out instantly whether a no-drill retrofit smart lock will fit before you buy.
Check your door → Free toolPaint Coverage Calculator
Enter your wall area, doors, and windows — find out exactly how many gallons and quarts you need, minus the waste.
Calculate paint → Free toolAir Fryer Size Picker
Tell us your household size and cooking style — get the right air fryer capacity in quarts, no guesswork.
Pick your size → Free toolCurtain Size Calculator
Enter your rod width and style — get the right panel width, length, and how many panels to buy.
Calculate curtains → Free toolMattress Size Chooser
Tell us how many sleepers and your room size — get the right bed size with exact dimensions.
Choose your bed → Free toolShoe Size Converter
Enter your size in any system — convert instantly between US, UK, EU, and JP, plus foot length in cm.
Convert size → Free toolBra Size Calculator
Two quick measurements — get your true band and cup size, plus sister sizes for a perfect fit.
Find your size → Free toolRing Size Converter
Enter your ring size in any system — convert between US, UK, EU, and JP, plus diameter in mm.
Convert size → Free toolDog Crate Size Finder
Pick your dog’s breed or enter length and height measurements — get the right crate size with room to stand, turn, and lie down.
Find the crate size → Free toolJeans Size Converter
Enter your jeans size in any system — convert between US, UK, and EU sizes, plus waist and inseam in inches.
Convert jeans size → Free toolCostume Size Converter
Enter your measurements, get the right costume size — women, men and kids.
Find your costume size → Free toolHalloween Candy Calculator
How much candy to buy for your street — bags, pieces and cost.
Calculate candy →Every tool is free, works on mobile, and ends with hand-picked Amazon picks matched to your result. As an Amazon Associate we earn from qualifying purchases.