Find Your Bra Size Without a Tape Measure
No measuring tape? No problem! Use these clever household hacks to estimate your bra size accurately using items you already have.
Before You Start
For Best Results
- • Measure wearing a non-padded bra or no bra
- • Stand straight with arms at your sides
- • Keep your measuring tool level and parallel to the floor
- • Take measurements at the end of a normal exhale
What You're Measuring
- Underbust: Around your ribcage, directly under your breasts
- Bust: Around the fullest part of your chest (usually at nipple level)
- The difference between these determines your cup size
6 Ways to Measure Without a Tape
String or Ribbon Method
You'll Need:
- •String, yarn, ribbon, or shoelace
- •Ruler or yardstick
Steps:
- 1Wrap the string around your underbust, keeping it level and snug
- 2Mark where the string meets or pinch that spot
- 3Lay the string flat against a ruler to measure in inches
- 4Repeat for your bust measurement at the fullest point
- 5Use these measurements in our calculator
💡 Tip: Non-stretchy string works best for accurate results.
Paper Strip Method
You'll Need:
- •A4 or letter paper (8.5" wide)
- •Tape to join strips if needed
Steps:
- 1Cut or fold paper into long strips about 1-2 inches wide
- 2Tape strips together end-to-end for enough length
- 3Wrap around your body like you would a tape measure
- 4Mark where the paper overlaps
- 5Count how many paper widths (8.5") plus the extra marked portion
💡 Tip: Standard paper is 8.5 inches wide - use this as your base measurement unit.
Well-Fitting Bra Method
You'll Need:
- •A bra that fits you well (even if old)
Steps:
- 1Find a bra that fits comfortably - band snug, cups containing tissue
- 2Check the tag for the size
- 3If the band rides up, try a band size down; if too tight, try one up
- 4If cups gap, try a smaller cup; if tissue spills, try larger
- 5Use sister sizes if between sizes
💡 Tip: Even if the exact size isn't perfect, it gives you a starting point to adjust from.
Hand Span Method (Rough Estimate)
You'll Need:
- •Just your hand
Steps:
- 1Average adult hand span (thumb to pinky, spread) is about 8-9 inches
- 2Wrap your hands around your underbust, counting spans
- 3Most people need 3.5-4.5 hand spans for their underbust
- 4Multiply spans by your hand width (measure once against a known length)
- 5This gives a rough underbust estimate
💡 Tip: This is least accurate but works in a pinch. Verify with another method when possible.
Belt Method
You'll Need:
- •A belt with inch markers
- •Or mark your belt and measure later
Steps:
- 1Many belts have size markings in inches
- 2Wrap the belt around your underbust (buckle side out for reading)
- 3Note where it sits comfortably snug
- 4Read the inch marking or mark the spot to measure later
- 5Repeat for bust measurement
💡 Tip: Men's belts often have clearer inch markings.
Smartphone Method
You'll Need:
- •Smartphone
- •String or paper strip
Steps:
- 1Look up your phone's exact dimensions online
- 2Most phones are 5.5-6.5 inches tall
- 3Wrap string around body, mark it
- 4Lay string against your phone, counting phone-lengths
- 5Multiply phone-lengths by phone height for inches
💡 Tip: iPhone 14 is 5.78", Samsung S23 is 5.76", Pixel 7 is 6.13".
Quick Reference: Common Object Sizes
| Object | Size in Inches | Size in CM |
|---|---|---|
| US Letter Paper (width) | 8.5" | 21.6 cm |
| A4 Paper (width) | 8.27" | 21 cm |
| US Dollar Bill | 6.14" | 15.6 cm |
| Credit Card | 3.37" | 8.56 cm |
| iPhone 14/15 | 5.78" | 14.7 cm |
| iPhone 14/15 Pro Max | 6.33" | 16.1 cm |
Got Your Measurements?
Now use your underbust and bust measurements in our calculator to find your perfect bra size.
Calculate My Bra Size →Related Resources
Our content is researched, written, and regularly updated by our editorial team using the A Bra That Fits (ABTF) methodology — the same approach validated by the 500,000+ member r/ABraThatFits community. We cite peer-reviewed research, lingerie industry standards, and community data. Our calculators process data locally in your browser; we do not collect body measurements.
We use the modern 6-measurement ABTF method rather than the outdated +4 inch rule. This approach has been independently validated by the r/ABraThatFits community to produce more accurate and comfortable bra sizes than traditional two-measurement methods.