Free Home & DIY Tools Online
Paint calculator, wallpaper calculator, concrete calculator, shoe size converter, cooking converter. All tools run in your browser — no upload, no sign-up.
7 Tools
Wallpaper Calculator
Calculate rolls needed for any room.
Home
Paint Calculator
Estimate gallons of paint needed.
Home
Concrete Calculator
Calculate concrete volume in cubic yards.
Home
Shoe Size Converter
Convert between US, UK, EU sizes.
Home
Cooking Converter
Convert cups, tablespoons, ml, grams.
Home
Tile Calculator
Calculate tiles needed for floors and walls.
Home
Plant Watering Reminder
Track plant care schedules with watering reminders.
Home
Frequently Asked Questions
Yes, all home and DIY tools on OptiDrop are 100% free with no usage limits, no sign-up, and no watermarks. Use them as often as you need.
No. All calculations happen entirely in your browser. Your room dimensions, paint preferences, and other data never leave your device.
Yes. These calculators accept custom wall dimensions, and you can subtract doors and windows for accurate estimates. They work for rectangular, L-shaped, and irregular rooms by entering each wall separately.
Yes. All home tools are fully responsive and work perfectly on phones, tablets, and desktops. Take them to the hardware store on your phone for quick calculations.
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Last updated: June 2026