Fabric shrinkage calculator
Open Fabric shrinkage calculator on Happytails.ai. This view has the same page content and links, with explicit tool capabilities. Read the processing notes before using a tool.
Tool capabilities
{
"id": "fabric-shrinkage-calculator",
"category": "calculators",
"built": true,
"requirements": "Shrinkage from -50% to 95%. No automatic fabric rates or guarantees of future wash behavior.",
"implementation": {
"fields": [
{
"key": "mode",
"label": "Shrinkage input",
"value": "Measured sample",
"type": "select",
"values": [
"Measured sample",
"Known percentages"
]
},
{
"key": "beforeWidth",
"label": "Sample width before washing",
"value": 20,
"type": "number",
"min": 0,
"max": 1000000000,
"step": "any",
"showWhen": {
"mode": [
"Measured sample"
]
}
},
{
"key": "afterWidth",
"label": "Sample width after washing",
"value": 19,
"type": "number",
"min": 0,
"max": 1000000000,
"step": "any",
"showWhen": {
"mode": [
"Measured sample"
]
}
},
{
"key": "beforeLength",
"label": "Sample length before washing",
"value": 20,
"type": "number",
"min": 0,
"max": 1000000000,
"step": "any",
"showWhen": {
"mode": [
"Measured sample"
]
}
},
{
"key": "afterLength",
"label": "Sample length after washing",
"value": 18,
"type": "number",
"min": 0,
"max": 1000000000,
"step": "any",
"showWhen": {
"mode": [
"Measured sample"
]
}
},
{
"key": "sampleUnit",
"label": "Sample measurement unit",
"value": "cm",
"type": "select",
"values": [
"mm",
"cm",
"m",
"in",
"ft",
"yd"
],
"showWhen": {
"mode": [
"Measured sample"
]
}
},
{
"key": "widthShrink",
"label": "Width shrinkage (%)",
"value": 5,
"type": "number",
"min": -50,
"max": 95,
"step": "any",
"showWhen": {
"mode": [
"Known percentages"
]
}
},
{
"key": "lengthShrink",
"label": "Length shrinkage (%)",
"value": 10,
"type": "number",
"min": -50,
"max": 95,
"step": "any",
"showWhen": {
"mode": [
"Known percentages"
]
}
},
{
"key": "targetWidth",
"label": "Desired after-wash width",
"value": 50,
"type": "number",
"min": 0,
"max": 1000000000,
"step": "any"
},
{
"key": "targetLength",
"label": "Desired after-wash length",
"value": 100,
"type": "number",
"min": 0,
"max": 1000000000,
"step": "any"
},
{
"key": "targetUnit",
"label": "Desired size and output unit",
"value": "cm",
"type": "select",
"values": [
"mm",
"cm",
"m",
"in",
"ft",
"yd"
]
},
{
"key": "allowance",
"label": "Extra after-wash allowance on each edge",
"value": 0,
"type": "number",
"min": 0,
"max": 1000000000,
"step": "any"
},
{
"key": "allowanceUnit",
"label": "Allowance unit",
"value": "cm",
"type": "select",
"values": [
"mm",
"cm",
"m",
"in",
"ft",
"yd"
]
}
],
"input": false,
"live": true,
"presentation": "metrics",
"note": "Calculate the dimensions to cut before washing. Width and length can shrink differently. Negative shrinkage means growth; allowances are specified at the final, after-wash size. Changing units keeps the entered numbers. All calculations stay on your device. Download the report for formulas, assumptions and calculated values.",
"experience": {
"automatic": true,
"single": false,
"inputMaxLength": 1000000,
"inputMode": "text",
"label": "Your text",
"placeholder": "Type or paste your input…",
"help": "Change the input or settings to update your result. Results update as you type. Up to 1,000,000 characters.",
"helpParts": [
"Change the input or settings to update your result.",
"Results update as you type.",
"Up to 1,000,000 characters."
],
"action": null
},
"mode": "automatic",
"interactive": false
},
"execution": "Browser interface",
"api": null,
"browser_agent": {
"supported": true,
"name": "run_current_tool",
"discovery": "WebMCP on the human page in a supporting browser",
"verification": "See audit/API-AUDIT.md; availability is not verification"
}
}Page guide
Calculate before-wash cut dimensions from measured fabric shrinkage. Keep width and length separate and add your finishing allowance.
How to use Fabric shrinkage calculator
- Enter the measured inputs and select their units.
- Review the calculated dimensions, counts and rounding.
- Download the result and verify it against a sample before making the full project.
Useful next steps
Measure both fabric directions
Wash and dry a sample using the process planned for the finished project. Measure the same width and length before and after. Alternatively, enter the two shrinkage percentages directly; negative percentages describe growth.
Allow for the final dimensions
Cut size is final size divided by the retained proportion. At 5% width shrinkage, a desired 50 cm width needs about 52.6316 cm before washing. An allowance entered per edge is added to the after-wash dimensions before the shrinkage correction.
Save the calculation
Download a CSV of the results or instructions, a readable text report and a JSON report with values, formulas and assumptions. Calculations run locally on your device. Unit changes keep the numbers already entered, so check the selected units before using the result.