Jacket Size Calculator
Determine your suit jacket or blazer size by inputting your measurements. Get fit guidance (slim, regular, athletic, portly) and recommended jacket length.
Recommended Size
44
US / UK: 44 | EU: 54
Fit & Drop
Fit: REGULAR
Drop (Chest − Waist): 6.0"
Length Suggestion
Jacket length: Regular
Regular fit: classic drop 6 silhouette fits most off-the-rack jackets.
How to Use This Calculator
Measure your chest
Wrap a tape around the fullest part of your chest, keeping it level and snug but not tight.
Record waist and height
Measure your natural waist and note your height to determine jacket length.
Review suggested size
Use the recommended size and fit as a starting point when trying on jackets or ordering online.
Formula
US Jacket Size ≈ nearest even number to chest measurement
EU Size = US Size + 10
Drop = Chest − Waist → determines fit category
Fit thresholds: Slim (drop ≥ 7"), Regular (6"), Athletic (4-5"), Portly (≤ 3").
Length guide: Short < 5'7", Regular 5'7"–5'11", Long 6'–6'3", Extra-Long > 6'3".
Example: Chest 42", Waist 36", Height 5'10" → Size 42R, drop 6" → Regular fit.
About the Jacket Size Calculator
Suit sizing can be confusing. This calculator provides an easy reference to convert body measurements into jacket sizes, helping you shop smarter and plan alterations.
When to Use This Calculator
- Before shopping: Know your base size before trying jackets on or shopping online.
- Wedding or event planning: Provide groomsmen or attendees with sizing guidance.
- Tailoring: Compare off-the-rack sizes against bespoke measurements.
- Weight changes: Track how body changes affect jacket size and fit.
Why Use Our Calculator?
- ✅ Comprehensive output: US, UK, EU sizes plus fit and length.
- ✅ Fit insights: Understand whether you need slim, regular, athletic, or portly cuts.
- ✅ Alteration notes: Quick suggestions for tailoring adjustments.
- ✅ Mobile friendly: Use from the fitting room or tailor shop.
Common Applications
Stylists: Pair clients with the right brands and cuts.
Rental shops: Size customers quickly for tuxedos.
Fashion students: Use as reference when drafting pattern blocks.
Tips for Best Results
- Measure over a thin shirt or undershirt for accuracy.
- Check brand-specific guides; some European brands use different drops.
- Remember that tailoring can fine-tune the fit even if the base size is slightly off.
- If between sizes, size up and alter down for a sharper silhouette.
Frequently Asked Questions
What is a jacket “drop”?
Drop is the difference between chest and waist measurements. Off-the-rack jackets assume a drop of 6". Larger drops indicate a V-shaped torso.
How do I find sleeve length?
This calculator focuses on chest size. Sleeve length is determined by arm measurement; most brands offer short, regular, and long sleeve variations.
Do women’s blazers use the same sizing?
No. Women’s jackets use a different size range and shaping. This calculator is intended for men’s or unisex jacket sizing.
Should I size up for layering?
If you plan to wear thick sweaters under your blazer, consider sizing up one size or choosing a more generous fit.