# Construction Calculators

Materials and layout maths for concrete, paint, stairs, roofs, lumber, tile, drywall, fences and decks.

## How to pay

Machine-payable over x402. USDC on: Base (eip155:8453), Solana (solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp), Polygon (eip155:137), Arbitrum One (eip155:42161).
No accounts. No API keys. No signup. The paying wallet is the account.

## Machine-readable

- OpenAPI: https://construction-calc.x402tookit.com/openapi.json
- x402 manifest: https://construction-calc.x402tookit.com/.well-known/x402
- Catalog (free): https://construction-calc.x402tookit.com/catalog
- Health (free): https://construction-calc.x402tookit.com/health
- Uptime (free): https://construction-calc.x402tookit.com/uptime

## Endpoints (10)

### GET /board-feet — $0.02
Board feet for lumber from thickness, width, length and quantity (nominal sizes), with total cost at a price per board foot.
Params: thicknessIn: number, widthIn: number, lengthFt: number, quantity?: integer, pricePerBoardFoot?: number
Example: https://construction-calc.x402tookit.com/board-feet?thicknessIn=2&widthIn=4&lengthFt=8&quantity=10

### GET /bulk-material — $0.02
Cubic yards and approximate tons of gravel, sand, topsoil, mulch or compost to cover an area at a given depth.
Params: material: string, areaSqFt: number, depthIn: number, pricePerYd3?: number, compactionPct?: number
Example: https://construction-calc.x402tookit.com/bulk-material?material=gravel&areaSqFt=200&depthIn=3

### GET /concrete-volume — $0.02
Concrete for a slab: cubic yards with waste, ready-mix order size and the number of 40, 60 or 80 lb bags of mix.
Params: lengthFt: number, widthFt: number, thicknessIn: number, wastePct?: number
Example: https://construction-calc.x402tookit.com/concrete-volume?lengthFt=10&widthFt=10&thicknessIn=4&wastePct=10

### GET /deck-calc — $0.02
Decking boards, joist count and screws for a rectangular deck from its size, board width, gap, joist spacing and stock length.
Params: lengthFt: number, widthFt: number, boardWidthIn?: number, gapIn?: number, joistSpacingIn?: number, stockLengthFt?: number, wastePct?: number
Example: https://construction-calc.x402tookit.com/deck-calc?lengthFt=16&widthFt=12&boardWidthIn=5.5&gapIn=0.125&joistSpacingIn=16&stockLengthFt=16

### GET /drywall-calc — $0.02
Drywall sheets for a room's walls and ceiling (4x8, 4x10 or 4x12), with waste, screw count and approximate weight.
Params: lengthFt: number, widthFt: number, heightFt: number, doors?: integer, windows?: integer, includeCeiling?: string, sheetSize?: string, thicknessIn?: number, wastePct?: number
Example: https://construction-calc.x402tookit.com/drywall-calc?lengthFt=12&widthFt=14&heightFt=8&doors=1&windows=2&sheetSize=4x8

### GET /fence-calc — $0.02
Posts, rails and pickets for a straight fence from its length, post spacing, picket width and gap.
Params: lengthFt: number, heightFt?: number, postSpacingFt?: number, picketWidthIn?: number, picketGapIn?: number, gates?: integer, wastePct?: number
Example: https://construction-calc.x402tookit.com/fence-calc?lengthFt=100&heightFt=6&postSpacingFt=8&picketWidthIn=5.5&picketGapIn=0.5

### GET /paint-coverage — $0.02
Gallons of paint for a room from its size, doors, windows and coats; optional ceiling. Rounds up to the quart.
Params: lengthFt: number, widthFt: number, heightFt: number, doors?: integer, windows?: integer, coats?: integer, coverageSqFtPerGallon?: number, includeCeiling?: string
Example: https://construction-calc.x402tookit.com/paint-coverage?lengthFt=12&widthFt=14&heightFt=8&doors=1&windows=2&coats=2

### GET /roof-pitch — $0.02
Convert roof pitch (rise per 12), angle or percent slope; get the rafter length multiplier and roof area factor.
Params: pitch?: number, angleDeg?: number, percent?: number, runFt?: number
Example: https://construction-calc.x402tookit.com/roof-pitch?pitch=6&runFt=12

### GET /stair-calc — $0.02
Stair layout from total rise: number of risers, exact riser height, total run, stringer length, angle and a code check.
Params: totalRiseIn: number, treadDepthIn?: number, targetRiserIn?: number
Example: https://construction-calc.x402tookit.com/stair-calc?totalRiseIn=108&treadDepthIn=10&targetRiserIn=7.5

### GET /tile-calc — $0.02
Tiles needed for a floor or wall from area or room size, tile size, grout gap and waste, plus boxes if you give tiles per box.
Params: areaSqFt?: number, lengthFt?: number, widthFt?: number, tileWidthIn: number, tileHeightIn: number, groutGapIn?: number, wastePct?: number, tilesPerBox?: integer
Example: https://construction-calc.x402tookit.com/tile-calc?areaSqFt=100&tileWidthIn=12&tileHeightIn=12&groutGapIn=0.125&wastePct=10

## Terms

Estimates from standard formulas and typical coverage rates. Real jobs need allowances for site conditions; building codes vary by place and edition. Not engineering, structural or code-compliance advice: confirm with the product label, a supplier and your local building department.