Pit-to-pit quick check
Keep the listing’s flat width, the doubled garment circumference equivalent, your body chest and a known-good shirt as separate pieces of evidence.
Measure between the marked landmarks without stretching the garment. Use the same landmarks when comparing two pieces.
Measure between the marked landmarks without stretching the garment. Use the same landmarks when comparing two pieces.
Measurement consistency matters
A number is only useful when you know whether it is a body circumference, a flat garment width, or a linear finished-garment measurement.
- Pit to pit is a finished-garment width, not a body circumference.
- Use a straight horizontal line and a repeatable underarm landmark.
- Double a flat width only when you specifically need a circumference equivalent at the same garment level.
- A known-good garment is usually a stronger personal benchmark than a size label.
- If the garment has unusual armholes or no clear seam, document the exact endpoints and use the same method on the comparison garment.
Step-by-step method
- 1
Choose a comparable garment and close its front opening so the panels sit in their normal position.
- 2
Lay it flat on a firm surface and smooth wrinkles with your hands without pulling the fabric outward.
- 3
Find the underarm seam junction or another repeatable underarm edge on each side.
- 4
Place the tape straight across the garment at that level; do not curve the tape around the chest.
- 5
Record the result as a flat width with the unit and measurement method, for example “22.0 in pit to pit, seam to seam.”
- 6
Measure a garment you already like in exactly the same way and compare the two flat widths before considering shoulder, length and sleeve.
Worked example
Your favorite shirt measures 21.5 in pit to pit. A resale listing measures 22.25 in using the same method. The candidate is 0.75 in wider when laid flat, or about 1.5 in more around at that chest level. That is useful evidence that the candidate is roomier through the chest, but it says nothing yet about shoulder width, body length or sleeve length.
Common mistakes that change the answer
- Measuring your body from armpit to armpit and calling that pit to pit.
- Stretching knit fabric or pulling the garment taut before measuring.
- Following a curved seam instead of measuring a straight flat width.
- Comparing a flat pit-to-pit number directly with a body chest circumference.
- Treating doubled pit to pit as a universal body-size or fit recommendation.
- Comparing two garments measured from different underarm landmarks.
When the related tool helps
Use the calculator after you have confirmed the measurement method or product-specific chart. Arithmetic can be exact while the fit or care decision still depends on construction, brand rules or your personal reference garment.
Continue with the working tool
The related tool starts with blank inputs and keeps its assumptions visible.
Open related tool →Continue this decision path
Questions people ask
Is pit to pit a body measurement?
No. In clothing listings, pit to pit normally refers to a flat finished-garment width across the chest. Measure your body chest as a circumference instead.
Do I double pit to pit?
Double it only when you need an approximate full garment circumference at the same level. Keep the original flat width for garment-to-garment comparisons.
Where exactly do I start the tape?
Use the underarm seam junction when it is clear. If the garment has a different construction, choose a repeatable underarm edge and record the method so another garment can be measured the same way.
Can pit to pit tell me my clothing size?
Not by itself. It is much more useful for comparing a candidate garment with one you already own or with finished-garment measurements from the same brand.
What should I ask a resale seller for besides pit to pit?
For most tops, shoulder width and back/body length are the next useful measurements; sleeve length is also important for long-sleeve garments.