The answer, measured. Free online tools that just work.
Calculators and converters for real jobs — reading shift times, ordering gravel, checking your PTO. No sign-up, nothing uploaded, every formula shown.
Money & Work
VAT Calculator
Add or remove VAT at any rate — see net, tax, and gross instantly.
PTO Accrual Calculator
See how much paid time off you've earned and when you'll reach your goal.
Overtime Pay Calculator
Time and a half made exact — your overtime rate and total weekly pay.
Time Card Calculator
Weekly hours from clock-in, clock-out, and breaks — with overtime split.
Construction & DIY
Gravel Calculator
Work out how many tons or cubic yards of gravel your project needs.
Concrete Calculator
Slabs, footings, and columns — get cubic yards and how many bags to buy.
Roof Pitch Calculator
Convert rise and run to pitch, angle, and rafter length in one step.
Mulch Calculator
Cubic yards and bags of mulch for your beds, at the right depth.
Topsoil Calculator
Cubic yards, tons, and bags of topsoil for lawns, beds, and leveling.
Paver Sand & Base Calculator
Gravel base and bedding sand for your patio — both layers in one go.
Fence Post Concrete Calculator
How many bags of concrete for your fence posts — by hole size and count.
Stair Stringer Calculator
Riser height, tread count, and stringer length from your total rise.
Board Foot Calculator
Board feet and lumber cost from thickness, width, length, and quantity.
Epoxy Resin Calculator
Gallons, liters, and ounces of mixed epoxy for tables, molds, and coats.
Asphalt Calculator
Hot-mix asphalt tonnage for driveways and paths, with waste allowance.
Wall Stud Calculator
Studs and plates for your wall framing, at 16 or 24 inch spacing.
Sod Calculator
Square feet, rolls, and pallets of sod for your new lawn.
Cord of Wood Calculator
Turn your firewood stack size into full cords and face cords.
Baseboard & Trim Calculator
Linear feet of baseboard for any room, minus doorways, plus waste.
French Drain Gravel Calculator
Tons of drainage gravel for your trench, minus the pipe volume.
Retaining Wall Block Calculator
Blocks, rows, and cap units for your wall from length and height.
Deck Stain Calculator
Gallons of stain for your deck and railings, at one or two coats.
Grass Seed Calculator
Pounds of seed for a new lawn or overseeding, by grass type.
Deck Board Calculator
Boards, linear feet, and screws for your deck surface.
Tile Calculator
Tiles and boxes for your floor or wall, with the right waste factor.
Concrete Steps Calculator
Cubic yards and bags for solid poured concrete steps.
Insulation Calculator
Square feet of insulation to buy, with R-value guidance by climate.
Roof Shingle Calculator
Squares and bundles of shingles from your roof footprint and pitch.
Wallpaper Calculator
Rolls of wallpaper from wall size, roll type, and pattern repeat.
Sand Calculator
Tons, cubic yards, and bags of sand for sandboxes and fill.
Deck Baluster Calculator
Evenly spaced balusters that pass the 4-inch code rule.
Fence Picket Calculator
Pickets, posts, and rails for your fence run in one calculation.
Pond Liner Calculator
The liner sheet size your pond needs, with depth and overlap included.
Mortar Calculator
Bags of mortar for your block or brick count — or straight from wall size.
Fire Pit Calculator
Blocks or pavers for a round or square fire pit, plus the gravel base.
Plywood Sheet Calculator
How many 4×8 sheets of plywood or OSB to cover a floor, wall, or roof.
River Rock Calculator
Tons and cubic yards of river rock or decorative stone for beds and borders.
Polymeric Sand Calculator
Bags of polymeric jointing sand for paver and flagstone joints.
Carpet Calculator
Square yards and square feet of carpet for your rooms, with waste.
Raised Bed Soil Calculator
Cubic feet and bags of soil for raised beds — with a recommended mix.
Food & Drink
Pizza Dough Calculator
Flour, water, salt, and yeast for any number of dough balls and hydration.
Coffee to Water Ratio Calculator
Grams of coffee and water for any brew ratio, by method and number of cups.
Smoker Cook Time Calculator
When to put brisket, pork, or ribs on so they're done when you want to eat.
Party Food Calculator
How much meat, sides, appetizers, and dessert to make by guest count.
Party Alcohol Calculator
Bottles of beer, wine, and liquor to buy for your guests and party length.
Home & Garden
Aquarium Volume Calculator
Gallons, liters, and filled water weight for any tank shape and size.
Picture Hanging Height Calculator
Exact nail height to center art at 57-60 inches, with wire sag and galleries.
Christmas Light Calculator
How many light strands for your roofline, tree, and bushes — plus amp draw.
Games & Hobbies
Darts Checkout Calculator
Enter your remaining score and get the standard 501 checkout route.
Riichi Mahjong Score Calculator
Han, fu, dealer or not — get the exact payout without the score table.
Guitar Metronome
Online metronome with real volume control, tap tempo, and a speed trainer.
Capo Calculator
Where to clamp your capo to play any key with easier open-chord shapes.
Tap Tempo — BPM Tapper
Tap along to any song to measure its tempo in BPM instantly.
Yahtzee Score Calculator
Fill in a scorecard and get the running total, upper bonus, and all.
Why HatchCalc
Every tool here runs directly in your browser — nothing you type is ever uploaded to a server. That makes the tools fast, private, and available even on a flaky connection once the page has loaded.
No accounts, no paywalls, no "free trial". Each tool also explains the exact formula or method behind it, so you can trust (and verify) the results.