Actual Size Viewer — Everyday Objects at Real Size
Pick an object to see it at its true size. Hold a real coin, bill or card against it to calibrate your screen.
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This object is larger than your screen. Scroll sideways to see all of it.
Match a real object to calibrate Hold it against the shape. If the sizes differ, adjust until they match, then save.
Not calibrated yet, so sizes may be off. Match a real object below.Saved. Every ruler on this site now uses this calibration.
See how big things really are
Wondering how big 1 inch is, or whether a pendant shown online is the size of a dime? This viewer draws everyday objects at their true size on your screen. It also works the other way: hold a real coin or bill against the shape, adjust until they match, and your screen is calibrated for every ruler on this site.
Related guides: How to Measure Without a Ruler · How to Measure Your Ring Size at Home
How to use it
- Pick an object, such as a US quarter or a dollar bill.
- Hold the real object flat against the shape on your screen.
- If the sizes differ, use − and + until they match exactly, then tap Save calibration.
Good to know
- A US quarter is 24.26 mm (0.955 in) across; a penny is 19.05 mm (0.750 in).
- A US dollar bill measures 6.14 × 2.61 inches (156 × 66.3 mm).
- Larger objects give a more accurate calibration: a dollar bill is better than a dime.
Three ways to calibrate
Auto-detect your device
The ruler recognizes about 130 phones, tablets, laptops and monitors, including iPhones, Galaxy phones, Pixels and MacBooks.
Enter your screen size
Enter your screen's diagonal size (for example, 15.6" for a laptop), and the ruler works out the scale from your screen resolution.
Calibrate with a bank card
Hold any bank card against the outline on screen and move the slider until they match. Bank cards are the same size everywhere: 85.60 × 53.98 mm.
How accurate is the ruler?
How accurate the ruler is depends on how well it knows your screen's pixel density, meaning how many pixels fit in an inch. There are three ways to set it, from most to least accurate:
Bank card (±0.5%): Bank and credit cards are made to one worldwide size, 85.60 × 53.98 mm (ISO/IEC 7810 ID-1). Because every card is exactly the same, matching one on screen gives the most accurate result.
Auto-detect (±1%): The ruler looks up your device's published screen size and resolution. Screens of the same model can differ very slightly, so this is a little less exact. It covers about 130 devices.
Screen size (±2%): You type in your screen size, and the ruler works out the rest from your resolution. Advertised sizes are rounded (a "15.6-inch" screen may really be 15.59 inches), so this is the least exact method. It's a good fallback when you don't have a card.
Real-life objects to check your measurements
Use these everyday objects to confirm the ruler is calibrated correctly.
Bank or credit card: 85.60 × 53.98 mm (3.37 × 2.13 in)
A4 paper: 210 × 297 mm (8.27 × 11.69 in)
US Letter paper: 8.5 × 11 in (215.9 × 279.4 mm)
US quarter: 24.26 mm (0.955 in) across
1 euro coin: 23.25 mm (0.915 in) across
AA battery: about 50.5 mm long and 14.5 mm wide
More online rulers
Measuring guides
- How to Measure Without a Ruler
- How to Measure Your Ring Size at Home
- Paper Sizes Chart (Inches and Millimeters)
- US Coin Sizes: Diameter, Thickness and Weight
- Picture Frame Sizes: Standard US and Metric Chart
- Envelope Sizes Chart: US and International
- Business Card Size: Standard Dimensions by Country
- Poster Sizes Chart: US and International
- Is an Online Ruler Accurate? How to Calibrate It
- How to Measure Inches on Your Phone
- How Big Is 1 Inch? Everyday Objects That Are an Inch
- How Big Is 1 cm and 1 mm? Real-Life Comparisons
- All guides →