Beauty Calculators
Wig size.
Measure around your head along the hairline and enter it to see which cap size you need: petite, average, large or extra large. Brands vary a little, so use the result as a guide next to the size chart of the wig you want. Runs in your browser.
Your head
Your cap size
Fill the form and press Calculate.
Worked example
Your tape reads 22 inches (55.9 cm) around the hairline. That falls in the 21.5 to 22.5 inch band, so you are an Average cap. A reading of 22.4 inches is still average but sits within a quarter of an inch of Large, so check both.
How to measure
Use a soft tape measure. Start at the front of your natural hairline in the middle of the forehead, run it just above and behind each ear, around the nape of the neck and back to the start. Keep it flat and snug, not tight. Do it twice and use the same reading both times. Measure over natural hair that is pinned flat or braided down, since that is what the cap will sit over.
Size bands used
| Cap size | Inches | Centimetres |
|---|---|---|
| Child / extra small | under 20 | under 50.8 |
| Petite | 20 to 21.5 | 50.8 to 54.6 |
| Average | 21.5 to 22.5 | 54.6 to 57.2 |
| Large | 22.5 to 23.5 | 57.2 to 59.7 |
| Extra large | over 23.5 | over 59.7 |
There is no official standard for wig sizes, so these are the common retail bands. Most wigs include an adjustable strap or elastic at the nape that adds a little give, and some brands sell Petite and Large caps separately. Always check the chart of the specific wig.
Sources and basis (checked 2026-10-05): common retail wig cap size conventions; inch to centimetre conversion 1 in = 2.54 cm exactly (NIST).
FAQ
What size wig do I need?
Measure your head around the hairline. About 21.5 to 22.5 inches (54.6 to 57.2 cm) is an average cap, which is the most common size. Under that is petite and over it is large.
Where do I measure my head for a wig?
Start at the front hairline, go just above the ears and around the nape of the neck, and back to the start. Use a soft tape measure and keep it snug.
What if I am between two sizes?
Look for a wig with an adjustable strap and compare the exact chart for that brand. If you are on the edge of a band, an average cap with a tightened strap is often more comfortable than one that is too tight.
Are wig sizes the same across brands?
Not exactly. Average is the usual default, but petite and large bands shift by brand, so use this as a guide and read each brand chart.
Do I measure with or without hair?
Measure over your hair as you will wear it under the wig, pinned flat or in a braid, not with loose volume.