Add a tip percentage and split the total evenly across diners.
You enter: Bill before tip · Tip percentage · People splitting
Example: Tip 15.30; total 100.30; each pays 50.15.
Open Tip and Bill Split →
Bags of premix from slab volume and per-bag yield.
You enter: Concrete volume · Yield per bag
Example: Exactly 60.00 bags; buy 60.
Open Concrete Bags Estimator →
Calculate an entered tip and tax amount, total bill, and equal share per person.
You enter: Subtotal · Tip rate · Tax rate · People sharing
Example: Tip = 15; total = 115; each person pays 57.50 currency units.
Open Tip, Tax, and Bill Split Calculator →
Estimate balloon count from an arch length, center-to-center balloon spacing, and an optional planning allowance.
You enter: Arch length · Balloon center spacing · Extra allowance
Example: Base count = 30; planned count = 33 balloons.
Open Balloon Arch Quantity Calculator →
Calculate internal volume and approximate litre capacity for a rectangular bag from dimensions and fill percentage.
You enter: Bag length · Bag width · Bag depth · Usable fill percentage
Example: Maximum volume = 24 L; usable capacity = 20.4 L.
Open Rectangular Bag Capacity Calculator →
Calculate the opposite point on Earth from a latitude and longitude using a spherical coordinate convention.
You enter: Latitude · Longitude
Example: Antipode = latitude −25.3°, longitude 99.8°.
Open Antipode Coordinate Calculator →
Calculate rectangular aquarium volume in litres and usable water volume from dimensions and a fill percentage.
You enter: Tank length · Tank width · Tank height · Fill percentage
Example: Maximum volume = 200 L; usable volume = 180 L.
Open Aquarium Volume Calculator →
Calculate rectangular bed area and a minimum mattress-covering size from bed length, width, and side allowance.
You enter: Bed length · Bed width · Side allowance per edge
Example: Bed area = 3 m²; cover size = 2.4 m × 1.9 m.
Open Bed Area and Linen Size Calculator →
Estimate fill volume for an ellipsoid-like bean bag from its three overall dimensions and a selected fill fraction.
You enter: Overall length · Overall width · Overall height · Fill fraction
Example: Usable fill volume ≈ 0.281 m³, or 281.5 L.
Open Bean Bag Filling Volume Calculator →
Estimate the inner radius, cut radius, and fabric area for a full-, half-, or quarter-circle skirt from waist, length, and allowance inputs.
You enter: Waist circumference · Finished skirt length · Cutting allowance at hem · Circle fraction
Example: A full-circle layout has an inner radius of about 11.46 cm, a cut radius of about 74.46 cm, and an ideal sector area of about 20,084 cm².
Open Circle Skirt Fabric Calculator →
Estimate dried or fired clay dimensions and volume change from wet dimensions and a stated linear shrinkage percentage.
You enter: Wet length · Wet width · Wet height or thickness · Linear shrinkage
Example: Each dimension becomes 90% of its wet value: 180 × 108 × 9 mm, with a final-to-initial volume ratio of 72.9%.
Open Clay Shrinkage Calculator →
Convert stitch counts and fabric count into stitched dimensions, cut dimensions, and approximate fabric area with a visible margin.
You enter: Stitches wide · Stitches high · Fabric count · Margin on each side
Example: The stitched design is about 8.57 × 6.43 in; with a 3 in margin on every side, the cut estimate is 14.57 × 12.43 in.
Open Cross-Stitch Fabric Size Calculator →
Estimate finished panel count, total cut width, and fabric area from a window width, fullness ratio, panel width, and drop.
You enter: Window or rod width · Center overlap allowance · Fullness ratio · Usable cut width per panel · Cut drop per panel
Example: Required finished width is 440 cm, so four 140 cm panels are needed; the ideal cut area is 13.44 m².
Open Curtain Panel Quantity Calculator →
Estimate the minimum flat width and length of a liner for a rectangular bin, then add visible fitting allowances before checking a product label.
You enter: Bin opening length · Bin opening width · Bin height · Extra flat-width allowance · Extra length allowance
Example: The opening perimeter is 140 length units; minimum flat width is 70, recommended width is 75, and recommended length is 90.
Open Garbage Bag Size Planner →
Calculate a mat outer size, frame outer size, visible artwork area, mat area, and frame perimeter from artwork and border measurements.
You enter: Artwork width · Artwork height · Mat border — left · Mat border — right · Mat border — top · Mat border — bottom · Frame reveal beyond mat
Example: The mat outer size is 30 × 37; the frame outer size is 34 × 41; mat area is 610 square units and frame perimeter is 150 length units.
Open Picture Frame and Mat Size Calculator →
Infer sheet caliper from a measured paper stack and project the height, inches, and sheets-per-inch for another sheet count.
You enter: Sheets in measured stack · Measured stack height · Target sheet count
Example: The estimated caliper is 0.1 mm (100 µm); 500 sheets project to 50 mm or about 1.9685 inches, equal to about 254 sheets per inch.
Open Paper Thickness and Stack Height Calculator →
Calculate the mass of paper sheets and a 500-sheet ream from grammage, sheet dimensions, and quantity.
You enter: Grammage · Sheet width · Sheet height · Sheet count
Example: An A4 80 g/m² sheet has area 0.06237 m² and mass about 4.9896 g; 500 sheets weigh about 2.4948 kg.
Open Paper Sheet Mass and Ream Weight Calculator →
Convert a rectangular stacked firewood pile into cubic feet, standard cord equivalents, and an entered purchase estimate.
You enter: Stack length · Stack height · Stack depth · Price per standard cord
Example: The pile occupies 128 ft³, equals 1 standard cord, and has an entered purchase estimate of 300 currency units.
Open Cordwood Volume Calculator →
Estimate the lift of one spherical helium balloon and the number needed for a payload after accounting for envelope mass and a visible planning margin.
You enter: Payload mass · Balloon diameter · Surrounding air density · Helium density · Envelope and hardware mass per balloon · Planning margin · Gravitational acceleration
Example: One balloon supports about 0.01179 kg net in this model; with a 20% planning margin, the estimate is 102 balloons.
Open Helium Balloon Lift and Quantity Calculator →
Convert measured wheel backspacing and advertised width into the approximate wheel offset, centerline, overall width, and outboard spacing.
You enter: Advertised wheel width · Measured backspacing
Example: An 8-inch advertised wheel is estimated at 9 inches overall; 4.75 inches of backspacing gives about +6.35 mm offset and 4.25 inches of outboard spacing.
Open Wheel Offset and Backspacing Calculator →
Estimate the line pull for moving a mass up a slope from grade, rolling resistance, line efficiency, and a visible safety factor.
You enter: Gross moving mass · Slope · Rolling-resistance coefficient · Line and pulley efficiency · Planning safety factor · Gravitational acceleration
Example: The model estimates about 2,755 N before the safety factor and a recommended planning pull of about 4,133 N, equivalent to about 421 kgf.
Open Winch Line Pull Planning Calculator →
Resolve a wind speed into runway-relative crosswind and headwind or tailwind components using a selectable speed unit.
You enter: Wind speed · Wind-speed unit · Wind angle from runway direction
Example: A 20-knot wind at 60° gives about 17.321 knots crosswind and 10 knots headwind.
Open Crosswind and Headwind Component Calculator →
Turn a dog's chest girth, neck girth, and back length into transparent measurement targets with user-entered fit clearances before comparing a manufacturer's size chart.
You enter: Chest girth at the widest ribcage · Neck girth at the harness position · Back length from neck base to tail base · Chest-girth fitting clearance · Neck fitting clearance · Back-length planning clearance · Measurement unit
Example: The planning targets are 65 cm chest, 37 cm neck, and 52 cm back length; compare those measurements with the exact harness maker's chart.
Open Dog Harness Measurement Planner →
Convert a measured inner circumference into diameter, inches, and an ISO-style numeric ring-size reference without hiding regional sizing differences.
You enter: Measured inner circumference · Measurement unit
Example: Inside diameter ≈17.1887 mm; circumference =2.12598 in; ISO-style numeric reference =14.
Open Metric Ring Size Planner →
Estimate lace length from eyelet pairs, eyelet spacing, across-shoe width, lacing style, and the total allowance needed for tying.
You enter: Eyelet pairs on one shoe · Across-shoe eyelet width · Vertical spacing between rows · Total allowance for tying · Lacing style model · Measurement unit
Example: Estimated thread path ≈72.03 cm; total recommended planning length ≈92.03 cm.
Open Shoelace Length Planning Calculator →
Estimate the mass of salt needed to move a pool from a measured concentration to a target concentration using litres, cubic metres, or US gallons.
You enter: Pool water volume · Volume unit · Current salt concentration · Target salt concentration · Salt product purity
Example: Pure salt required =150 kg; at 99% purity, product planning mass ≈151.515 kg.
Open Pool Salt Addition Planner →
Estimate the total mass, face value, and value density of repeated cash items from a user-entered count, denomination, and unit mass.
You enter: Number of identical items · Face value per item · Mass of one item · Currency label
Example: Total mass =650 g; face value =USD 100; value density ≈USD 153.846 per kg.
Open Cash Weight Estimator →
Project total mobile or broadband data use from average daily usage, active days, an overhead allowance, and a plan limit in the selected data unit.
You enter: Average daily data use · Days in planning period · Protocol and measurement overhead · Plan allowance · Data unit
Example: Projected usage =49.5 GB; plan share =99%; remaining allowance =0.5 GB.
Open Data Usage Budget Calculator →
Estimate vehicles per kilometre, per-lane density, flow per lane, and average spacing from a road segment observation.
You enter: Vehicles on the segment · Segment length · Number of lanes · Average speed
Example: Density = 30 vehicles/km; per-lane density = 15 vehicles/km/lane; flow = 900 vehicles/hour/lane.
Open Traffic Density and Flow Calculator →
Calculate how many identical tables are needed for a guest count, plus seats provided, unused seats, and occupancy.
You enter: Guests · Seats per table
Example: 6 tables provide 48 seats, with 0 unused seats and 100% modeled occupancy.
Open Tables Needed for Guests Calculator →
Turn a numeric amount into readable English currency words for supported international currencies, including major and minor units, with a clear warning for formal documents.
You enter: Numeric amount · Currency
Example: one thousand two hundred thirty-four dollars and fifty-six cents
Open Amount in Words Calculator →
Estimate a generator’s planning wattage and apparent-power requirement from continuous load, starting surge, overlap, reserve, and power factor.
You enter: Continuous running load · Additional starting surge · Starting-surge overlap · Planning reserve · Planning power factor
Example: Peak real load is 3,500 W; with 20% reserve the planning load is 4,200 W, equivalent to 5.25 kVA at an 80% planning power factor.
Open Generator Wattage Planning Calculator →
Plan an inside- or outside-mount blind size from opening measurements, depth, overlap, and mounting extensions without applying hidden manufacturer deductions.
You enter: Mount type · Window opening width · Window opening height · Available mounting depth · Product minimum depth · Outside overlap per side · Outside top extension · Outside bottom extension
Example: The inside-mount planning size is 120 × 150 units with a 2-unit depth margin; no factory deduction is applied.
Open Blind and Shade Size Planner →
Convert copper, silver, electrum, gold, and platinum pieces into a common copper value and a normalized purse display.
You enter: Copper pieces (cp) · Silver pieces (sp) · Electrum pieces (ep) · Gold pieces (gp) · Platinum pieces (pp)
Example: The purse is worth 2,107 cp, or 21.07 gp, and normalizes to 2 pp, 1 gp, 0 sp, 7 cp.
Open D&D Money Conversion Calculator →
Estimate a fifth-edition 2014 encounter's adjusted XP and compare it with the party's easy, medium, hard, and deadly thresholds.
You enter: Number of characters · Character level · Number of monsters · XP per monster
Example: Base XP is 1,400; the two-monster multiplier is 1.5×, giving 2,100 adjusted XP. For four level-5 characters this sits just above the medium threshold and below hard.
Open 5e Encounter Difficulty Calculator →
Plan a rectangular flag's fly length, face area, pole position, and remaining pole using a chosen hoist-to-fly ratio.
You enter: Hoist length · Fly-to-hoist ratio · Pole height · Bottom clearance
Example: A 1-unit hoist at a 1.9 ratio has a 1.9-unit fly and 1.9 square units of face area; its top is 2.5 units above the base with 3.5 units of pole above it.
Open Flag Size and Proportion Planner →
Calculate the internal volume of a straight hollow circular pipe from its diameters and length.
You enter: Outer diameter · Inner diameter · Pipe length
Example: Internal pipe volume is 0.00282743 m^3.
Open Hollow Pipe Volume →
Estimate gravel volume and mass from footprint, depth, waste, and bulk density.
You enter: Length · Width · Depth · Waste allowance · Bulk density
Example: The tool reports cubic feet, cubic yards, and approximate US tons.
Open Gravel and Aggregate Estimate →
Estimate riser count, actual riser height, tread count, total run, and stair angle from basic dimensions.
You enter: Total rise · Maximum riser height · Minimum tread depth
Example: The calculator chooses 11 risers at about 7.64 inches and 10 treads with a 100 inch total run.
Open Stair Geometry Calculator →
Calculate tire section height and overall diameter, then compare diameter and indicated-speed effects.
You enter: Original tire width · Original aspect ratio · Original wheel diameter · Comparison tire width · Comparison aspect ratio · Comparison wheel diameter
Example: The calculator compares the original and alternative overall diameters and estimates actual speed at 60 indicated.
Open Tire Size Comparison →
