⚡ RapidWebApp
← Main Screen Ruler Hub ISO Standard
Scale: 3.78 px/mm
Theme:
A
▲
B
▲
Snap Calipers:
Card Calibrator — Live Measurement

Every standard payment card, drivers license, and transit card in the world is manufactured to the exact same size: 85.60 mm (3.37 inches). Use yours to calibrate a perfect screen ruler.

Fractions (1/16")
3 3/8"
Decimal Inches
3.37 in
Millimeters
85.6 mm
Centimeters
8.56 cm

The Universal Credit Card Standard: ISO/IEC 7810 ID-1

Whether issued by Visa, Mastercard, American Express, or your local DMV, payment and identity cards adhere strictly to the ISO/IEC 7810 ID-1 standard: exactly 85.60 mm wide, 53.98 mm tall, with 3.18 mm rounded corners. This universal manufacturing consistency makes bank cards the world’s most accessible calibration reference.

✓ Works with Visa, Mastercard, Amex, Drivers Licenses, and ID cards.
✓ Simple interactive on-screen slider matches card outline in seconds.
✓ Eliminates the need for a physical tape measure to set up your screen ruler.
✓ Instant verification against coin and document size benchmarks.

Standard Reference Size Checklist

Item Name Metric Imperial Description
Standard Credit / Debit Card (ISO/IEC 7810 ID-1) 85.6 mm 3.37" Universal size for driver’s licenses, bank cards, and transit passes worldwide.
US Quarter Dollar Coin 24.26 mm 0.955" Standard 25-cent coin diameter, convenient for fast circle calibrations.
US One Dollar Bill ($1 Banknote) 156 mm 6.14" Federal Reserve banknote length (height is 66.3 mm / 2.61 in).
US Passport / ID Photo 50.8 mm 2" Exact 2 × 2 inches square requirement for US visa and passport headshots.
Standard Sticky Note (Post-it) 76.2 mm 3" Classic 3 × 3 inches square memo paper found on office desks.

Explore Other Screen Ruler Modes

View All Rulers →
Inches Ruler Imperial Scale

Accurate actual size screen ruler in inches. Features 1/16-inch fractional ticks, dual draggable calipers, and instant credit card calibration.

Open Dedicated View →
CM & MM Ruler Metric Scale

Free online metric screen ruler displaying exact centimeters (cm) and millimeters (mm). Calibrate with any bank card for 1:1 physical accuracy.

Open Dedicated View →
Actual Size Ruler 1:1 True Scale

True 1:1 actual size screen ruler for desktop monitors, laptops, tablets, and smartphones. Guaranteed 100% physical accuracy with instant card calibration.

Open Dedicated View →
✓ Measurement copied!
🛡️ 100% Client-Side • Instant & Auto-Saved Locally

Credit Card Ruler Calibration — Calibrate Screen Ruler with Any Card

⚡ Quick Tools

Calibrate your screen ruler accurately in 5 seconds using any standard credit card, driver’s license, or gift card (ISO/IEC 7810 ID-1 standard).

⭐ 4.8/5 (175 votes)
✓ Link copied to clipboard!
⚡

Related Tools & Study Breaks

View All Tools →
🎡 Wheel of Names

Customizable spinning wheel with sound effects, winner elimination, and confetti.

🎲 Dice Roller

Roll D4, D6, D8, D10, D12, D20 dice with modifier support and roll history log.

⚡ Reaction Time

Test your visual reflexes down to the millisecond with standard and F1 Start Lights mode.

Frequently Asked Questions

Quick answers about controls, features, accuracy, and local browser saving.

Does the thickness of my card matter?
No. Only the width (85.60 mm / 3.37 inches) along the long edge is used for horizontal scale calibration.
Are gift cards and hotel keycards the exact same size?
Yes! Nearly all modern plastic gift cards, hotel keycards, and transit passes share the exact same ISO/IEC 7810 ID-1 form factor as credit cards.

💬 Player Comments & Community Tips

Share your record high scores, game strategies, or helpful tips with fellow players.

0 / 800

Loading community discussion...