Home & DIY
90 free home & diy tools in the Calculators & Converters collection — every one runs in your browser with no signup and no uploads.
3D Print Total Cost Per Gram
Factor electricity, machine depreciation, and failures into true print cost
3D Print Scale Factor Calculator
Find the scale percentage to resize a model to exact dimensions
3D Print Thread Sizing Chart
Find the correct hole diameter for printed internal threads (ISO, UNC, UNF)
Hot Water Boiler Output & Radiation Calculator
Match boiler net output to connected fin-tube baseboard and cast-iron EDR radiation.
Brick & Block Count Calculator
Estimate bricks or blocks required for any wall area with mortar joint
Room BTU Calculator
Size a window AC, mini-split or portable unit for a room with the ENERGY STAR method
Candle Wax & Fragrance Calculator
Calculate wax and fragrance oil amounts for any candle vessel
Composite Deck Material Calculator
Estimate lineal feet, boards, and fasteners for a composite deck
Concrete Anchor Pullout Strength Calculator
Estimate anchor bolt tensile capacity in concrete using ACI 318 concrete breakout
Crochet Gauge & Stitch Count Calculator
Scale any crochet pattern for your actual gauge
Cross Stitch Fabric Count Calculator
Calculate finished size for any cross stitch pattern on any fabric count
Deck Joist Span Calculator
Verify allowable joist span for any lumber size, species, and spacing
Drywall Sheet Calculator
Calculate drywall sheets, screws, tape, and mud for any room
Fabric Shrinkage Calculator
Calculate pre-washed fabric yardage needed accounting for shrinkage
Fetal Growth Centile Calculator (INTERGROWTH-21st)
Plot estimated fetal weight against gestational-age centiles
Floor & Wall Tile Calculator
Estimate tile count, thinset bags, and grout for any room with waste factor
Gas Appliance Total BTU/h Load Calculator
Sum gas appliance BTU/h ratings and verify meter and regulator capacity
Gravel & Aggregate Volume Calculator
Calculate cubic yards and tons of gravel, crushed stone, or sand for any area
Knitting Increase/Decrease Spacing Calculator
Evenly space increases or decreases over a run of rows or stitches
Home Insulation Payback Calculator
Calculate payback period and CO2 savings for loft or wall insulation
Knitting Blocking Dimensions Calculator
Calculate wet-blocked dimensions from dry measurements and yarn type
Knitting Gauge Converter & Stitch Calculator
Convert gauge swatches and recalculate stitch counts for any yarn
Knitting Provisional Cast-On Reference
Calculate stitch count and method for any provisional cast-on technique
Knitting Row & Round Counter
Count rows, rounds, and repeats for any knitting project
Knitting Sock Heel Turn Calculator
Calculate short-row heel or flap-and-gusset sock heel math
Lorcana Deck Consistency Score
Score Lorcana deck consistency from ink curve and card mix
Paint Coverage Calculator
Estimate gallons needed for any room based on coverage and coats
Pipe Insulation Heat Loss Calculator
Calculate heat loss per linear foot from bare vs insulated hot water or chilled water pipe.
Proof-of-Work Hash Demo
Interactively mine a block hash with adjustable difficulty in the browser
Radiant Floor Heating BTU Output Calculator
Calculate BTU/h output per square foot from radiant in-floor tubing spacing and water temperature.
Resin Print Support Angle Guide
Determine safe overhang angles without supports for resin SLA/MSLA prints
Roof Pitch & Rafter Length Calculator
Calculate rafter length, ridge height, and board count from span and pitch
Roofing Square & Material Calculator
Turn a roof footprint and pitch into squares, shingle bundles, and ridge cap
Soap Lye (Saponification) Calculator
Calculate NaOH or KOH lye amount for any soap oil recipe
Solar Farm Yield Estimator for Agricultural Land
Estimate annual kWh output and agrivoltaic revenue from solar-plus-agriculture installations
PV Panel Mismatch Loss Calculator
Estimate power loss from mixing panels with different Isc or Voc in a string
Solar Panel Daily/Monthly Output Calculator
Calculate expected kWh output from a PV array by watts, sun hours, and derate.
Stair Stringer Calculator
Calculate rise, run, stringer length, and angle for any stair height
Roof Drain & Stormwater Pipe Sizing Calculator
Size roof drains and leader pipes from roof area and design rainfall intensity per IPC 1106.
Wargame Terrain & Miniature Paint Coverage Calculator
Estimate paint pots needed for any miniature or terrain project
Reptile Terrarium Humidity & Misting Calculator
Calculate misting frequency to hold your target humidity
Yarn Yardage Estimator
Calculate yarn needed for any knitting or crochet project
Wallpaper Rolls Calculator
Work out how many rolls of wallpaper a room needs, including pattern repeat
Gravel Tonnage Calculator
Convert a driveway or path area and depth into tonnes of gravel or aggregate
Mulch Coverage Calculator
Work out how many bags of mulch, bark or compost a bed needs at a given depth
Decking Board Calculator
Count the decking boards a patio needs, including the expansion gap and waste
Air Conditioner BTU Calculator
Size a room air conditioner in BTU from floor area, sun, occupants and use
Tile Calculator
Work out how many tiles and boxes a wall or floor needs, with waste allowance
Laminate Flooring Calculator
Work out how many packs of laminate or engineered flooring a room needs
Grass Seed Calculator
Work out how much grass seed a lawn needs for sowing or overseeding
Fence Post Calculator
Count the posts, panels and postcrete a fence run needs from its length
Paint Calculator
How much paint to buy for any room — walls, coats and openings.
Tile Calculator
How many tiles to buy for a floor or wall, including waste.
Flooring Calculator
How many packs of laminate, vinyl or wood flooring to buy.
Concrete Calculator
Concrete volume and number of bags for a slab or footing.
Mulch Calculator
How much mulch, bark or compost to cover a garden bed.
Brick Calculator
Estimate how many bricks a wall needs, with a waste allowance.
Gravel Calculator
Work out the volume and weight of gravel for any area.
Fence Calculator
Count the posts, panels and rails for a fence run.
BTU Air Conditioner Calculator
Size an AC unit by working out the BTU your room needs.
Roof Pitch Calculator
Convert between rise/run, angle, percent and x-in-12 pitch.
BTU to kWh Converter
Convert BTU to kilowatt-hours and back, instantly.
Mulch & Soil Calculator
Bed size + depth → cubic yards or metres, bags needed and total cost.
Stairs Calculator
Turn total rise and run into steps, riser height, tread depth and stringer length — with building-code checks.
BTU Calculator
Size heating and cooling: room BTU plus the right air-conditioner.
Wallpaper Calculator
How many rolls of wallpaper you need — pattern repeat and cost included.
Fence and Gate Calculator
Run length, post spacing and gates to posts, panels, rails, concrete and cost.
Crushed Stone Calculator
Area, depth and material density to tonnes, bags and cost.
Asphalt Calculator
Turn area, depth and mix density into tonnes of asphalt — plus a cost estimate.
Flooring Calculator (Multi-Room, with Cost)
Packs of laminate, hardwood or vinyl across every room — plus cost and waste.
Brick Calculator
Wall area + brick size + mortar joint → bricks, mortar bags and cost.
Deck Building Calculator
Turn deck size into a board, joist and screw count — with a cost estimate.
Solar Panel Calculator
Size a solar array from your energy use or roof area — panels, output and savings.
Insulation Calculator
Area + target R-value + pack coverage → packs, rolls and cost.
Carpet Calculator
How much carpet to buy from a fixed-width roll — with waste, stairs and cost.
Drywall Calculator
Sheets of plasterboard, screws, compound and tape — with a cost estimate.
Paint Calculator
Wall area minus doors and windows, coats and coverage, to paint and cost.
3D Print Time & Material Estimator
Estimate print time, filament usage and material cost from model volume, infill and speed.
Board Foot Calculator
Instantly calculate board feet from lumber dimensions and get a material cost estimate.
Crochet Hook Size Converter
Instantly convert crochet hook sizes between US, UK and metric (mm).
Fabric Yardage Calculator
Enter your pattern pieces, pick a bolt width, and get the exact yardage to buy.
Knitting Gauge Calculator
Work out cast-on stitches and rows from your gauge swatch and target size.
Quilt Binding & Backing Calculator
Know exactly how much fabric to buy for binding and backing before you cut a single strip.
Yarn Yardage Calculator
Find exactly how many yards — and skeins — your knitting or crochet project needs.
Candle Wax Calculator
Work out exactly how much wax, fragrance oil and dye you need for any batch.
Epoxy Resin Calculator
Calculate exact Part A and Part B volumes for any mould shape and mix ratio.
Firewood Cord Calculator
Convert stack dimensions to full cords, face cords, BTU and seasonal cost.
Kerf Calculator
Calculate material loss from saw cuts and plan your cut list precisely.
Soap Lye Calculator
Calculate exact NaOH or KOH lye amounts for cold-process and liquid soapmaking.
Wood Shrinkage Calculator
Predict exact dimension loss as lumber dries from green to target moisture content.