Underwear Size Calculator & Chart – UK, US, EU Size Converter

Find your perfect underwear fit with our calculator. Convert between UK, US, and EU sizes instantly. Includes complete size charts and measurement guides.

Underwear Size Calculator

Find Your Perfect Fit Across UK, USA, and EU Sizing Standards

💡 Tip for Accurate Results: Take measurements on bare skin or with minimal clothing. Use a soft measuring tape and don't pull too tight. For women's bra sizing, measure while braless for maximum accuracy.
👩 Women's Underwear
👨 Men's Underwear
✅ Your Underwear Size:
📏 Women's Underwear Sizing Guide
Understanding Size Categories:
  • XS: Hip measurement 80-90 cm (31.5-35.5 in)
  • S: Hip measurement 90-100 cm (35.5-39.4 in)
  • M: Hip measurement 100-110 cm (39.4-43.3 in)
  • L: Hip measurement 110-120 cm (43.3-47.2 in)
  • XL: Hip measurement 120-130 cm (47.2-51.2 in)
  • 2XL: Hip measurement 130-140 cm (51.2-55.1 in)
Size Conversion Formula:

For hip-based sizing: Measure hips in cm, divide by 10, and round to nearest even number for EU size.

EU Size ≈ ⌊(Hip measurement ÷ 10)⌋ × 2

📏 Men's Underwear Sizing Guide
Size Categories by Waist Measurement:
  • XS/S: 75-80 cm waist (30-32 in)
  • M: 81-90 cm waist (32-36 in)
  • L: 91-100 cm waist (36-40 in)
  • XL: 101-110 cm waist (40-44 in)
  • 2XL: 111-120 cm waist (44-48 in)
  • 3XL: 121-130 cm waist (48-52 in)
Measurement Tips for Men:
  • Measure around your natural waistline where underwear normally sits
  • Keep the tape measure flat and level, but not too tight
  • Take measurement while standing relaxed
  • For undershirt sizing, measure chest at fullest point under arms
📊 International Underwear Size Conversion Chart
Women's Underwear - Complete Conversion Table:
UK Size US Size EU Size XS-XL Hip Range (cm) Hip Range (in)
6 2 34 XS 80-86 31.5-33.9
8 4 36 XS 86-92 33.9-36.2
10 6 38 S 92-98 36.2-38.6
12 8 40 M 98-104 38.6-40.9
14 10 42 L 104-110 40.9-43.3
16 12 44 L 110-116 43.3-45.7
18 14 46 XL 116-122 45.7-48
20 16 48 2XL 122-128 48-50.4
Men's Underwear - Complete Conversion Table:
UK/US Size EU Size International Waist (cm) Waist (in)
28-30 42 XS 75-80 30-32
30-32 44 S 80-86 32-34
33-36 46 M 81-90 33-36
37-40 48 L 91-100 37-40
41-44 50 XL 101-110 41-44
45-48 52 2XL 111-120 45-48
49-52 54 3XL 121-130 49-52
❓ Frequently Asked Questions
How do I measure my waist accurately? +
Stand relaxed and place a soft measuring tape around your natural waistline (typically where you wear pants or underwear). The tape should be level and snug but not tight. Breathe normally and read the measurement. For consistency, measure in the same conditions each time (e.g., time of day, after meals).
What's the difference between EU and UK underwear sizes? +
EU sizes use even numbers (34, 36, 38, 40, etc.) based on centimeter measurements of the body, while UK sizes also use even numbers (6, 8, 10, 12, etc.) but represent different measurement points. EU 34 ≈ UK 6 ≈ US 2. EU is based on standardized EN 13402 sizing, making it consistent across European countries.
Should I buy a size up if I'm between two sizes? +
For women, if measurements fall between sizes, choose based on hip measurement (use the larger size for comfort). For men, use the waist measurement to determine size. Generally, if between sizes, a larger size provides more comfort for daily wear, while a smaller size may feel snugger. Consider your personal preference for fit.
Does underwear size differ from clothing size? +
Yes, significantly. Underwear sizing is based on specific body measurements (waist, hips, bust) and follows stricter standards, whereas clothing sizes vary widely by brand and style. For example, you might wear a size 12 dress but a size 14 in underwear. Always calculate underwear size based on body measurements rather than your typical clothing size.
How often should I recalculate my size? +
Recalculate every 6-12 months as a general guideline, or whenever you experience significant weight changes. Body measurements can fluctuate due to seasonal changes, fitness routines, or life circumstances. Wearing the correct size improves comfort and fit, so it's worth verifying periodically, especially after major lifestyle changes.
What's the difference between underbust and band size for bras? +
Underbust measurement is taken directly under your bust (where the bra band sits), while band size refers to the circumference size of the actual bra. The band size is determined primarily by the underbust measurement. In US sizing, each 1-inch difference in underbust = 1 band size (28", 30", 32", etc.). Accurate underbust measurement is crucial for proper bra fitting.
Are there size variations between brands? +
Yes, significant variations exist. Different manufacturers have different fits, materials, and construction methods. A size 12 from one brand may fit differently than a size 12 from another. Always refer to specific brand sizing charts when available. Many premium brands provide detailed fit guides. Consider trying on multiple sizes when shopping online to account for these variations.
Can I use clothing sizes to estimate underwear size? +
Not reliably. While there may be some correlation, clothing sizes vary widely by brand and style, making them an inaccurate guide for underwear sizing. The most accurate method is taking direct body measurements and using those with standardized sizing charts or our calculator. Avoid guessing based on clothing size—spend the few minutes to measure for optimal fit and comfort.