6 Inch Ruler — Actual Size
A compact 6-inch (15.24 cm) ruler at actual size on your screen. 1/16" precision. Drag to measure any span. Calibrate for your monitor.
Place a physical credit card on your screen. Drag the slider until the dashed box matches the card exactly, then click Apply.
Reference Objects at Actual Size
Hold the real object against the screen to verify calibration.
About This 6 Inch Ruler
This ruler spans exactly 6 inches (15.24 cm) — half a foot. It's ideal for measuring smaller objects like credit cards, phone screens, envelopes, and craft cuts. The top scale shows inches at 1/16" precision; the bottom shows centimeters and millimeters.
Need to measure something longer? See the 12 inch ruler.
Frequently Asked Questions
Is this 6 inch ruler actual size?
Yes — when calibrated. The default 96 PPI is accurate for most desktop monitors. Click "Calibrate" and use a credit card to set your screen's exact pixel density for maximum accuracy.
How long is 6 inches in cm?
6 inches = 15.24 cm exactly. The formula: inches × 2.54 = cm. So 6 × 2.54 = 15.24 cm. You can see both scales on this ruler.
How long is 6 inches in mm?
6 inches = 152.4 mm. Multiply by 25.4: 6 × 25.4 = 152.4 mm. A standard 6-inch ruler is exactly 152.4 mm long.
What can I measure with a 6-inch ruler?
A 6-inch ruler is great for smaller objects: A5 paper (148 mm long), a credit card (85.6 mm), US dollar bill width (66.3 mm), phone screens, craft paper cuts, and other items under 15 cm.
How do I measure with this online ruler?
Place an object on your screen and align one edge with the 0 mark. Read where the other edge falls. Drag on the ruler to highlight any span — the measurement badge shows the exact length.
How accurate is an online 6-inch ruler?
At calibrated PPI, accurate to within 0.5 mm on most screens. For best results, calibrate using the credit card method: place a card on screen and drag the slider until the dashed box matches exactly.