Metric Scale Ruler

Variable Scale Ruler

This is an online scale ruler that could be calibrated to actual size and the scale ratio is variable that could be set by yourself, you can set the scale ratio according to your needs, eg. 1:50, 1:75, 1:100, 1:250, 1:500 ...etc. scale with metric units, centimeters(cm), meters(m) and kilometers(km). In order to let get you the most accurate measurement the length, we strongly recommend that you calibrate the ruler first, set the actual pixels per inch to your own device. If this ruler is useful to you, maybe your friends need it too, welcome to share it.

How to use this metric scale ruler ?

• Calibrate the ruler to actual size
• Set the scale ratio, for example "1:200"
• Black number is centimeter(cm), blue number is meter(m), green number is kilometer(km)
• Click on ruler will show a corresponding vertical line

How to adjusting this scale ruler to actual size

1. My laptop has a wide screen (13.6"x7.6"), and resolution is 1366x768 pixels, 1366 / 13.6 = 100.44 PPI. Screen resolution of current device is pixels.
2. Search "display by pixel density" online, check if there has your device's brand and model, i am lucky and found my screen has 100 PPI.
3. Use standard objects to compare lengths, check your wallet, use any paper money to be our compare object, then search "the width of your paper money" online, when you know the width, you can adjust the ruler's PPI setting by it, you can compare to any standard object, the longer the more accurate.
4. The most accurate way, after i measure the size of virtual ruler by an actual ruler, i found the markings are not very accurate at 30cm, so i adjust the default pixels per inch(PPI) to 100.7, now i get an online actual size ruler.
5. Each device has it's own PPI, eg. my laptop is 100.7 PPI, my mobile phones (Sony Xperia C5, OPPO R11 Plus) are both 122.6 PPI, Xiaomi Mi Pad 3 is 163 PPI. sorry, I don't have an iPhone to test for you, too expensive to me 😛

Dragging ruler adjuster left or right to fit the size of your reference object, remember to save the setting for next time, after save the setting, refresh your brower to check the result. On the most popular browsers you can press the F5 key or click on the refresh button.

Scale Calculators

1. Scale length converter : convert two lengths according scale ratio.
2. Scale factor calculator : find the scale ratio of two lengths.

What do you think about this virtual scale ruler ?

Try the scale ruler on your smartphone

Online rulers

• Actual size online ruler : the most accurate size ruler on the web.
• Metric scale ruler : variable scale ruler with metric units(cm, m, km)
• Imperial scale ruler : variable scale ruler with imperial units(in, ft, yd, mi)
• Online Protractor : use this transparent protractor to measure the angle of anything

Share to your good friends

Length Unit Converters

• Convert MM/CM to Inches : convert mm to inches, cm to inches, inches to cm/mm, include convert decimal inch to fractional inch (e.g. 1.45" = 1 7/16").
  Where is 1.8" in on a 12" ruler ? Where is the 3.2 cm in the 12 inches ruler ? Try this cm inch converter.
• Converter Meters to Feet : convert meters, feet and inches (m, ft and in), convert each other.
• Convert Yards to Meters : yards & meter converter, convert yards to meters, or meters to yards.
• Convert CM to MM : convert millimetre/millimeter(mm) to centimetre/centimeter(cm), or reverse convert.

How to use the scale ruler

A scale ruler a tool for measuring distances and transferring measurements at a fixed ratio of length; eg. architect's scale or engineer's scale.

An Architect's or scale ruler is designed for use in determining the actual dimensions of a distance on a scaled drawing. Most architectural, construction and engineering drawings and blueprints are scaled to allow for large areas, structures or items to conveniently fit on a reasonable size of paper.

Our virtual scale ruler has variable ratio, it could be set the ratio by yourself, eg. 1:10, 1:30, 1:75, 1:200, 1:500 ... The upper half of this scale ruler is the actual length; the lower half is the length calculated by the ratio.

What is the Metric Scale?

The metric scale is the system of measurement used in the metric system. Unlike the customary system of measurements in the United States, the metric scale has units based on multiples of 10. For example, in the United States distance measurements, one foot equals 12 inches, three feet are equal to one yard and 5,280 feet are equal to one mile. In the metric scale, 10 centimeters are equal to one decimeter, 10 decimeters are equal to one meter and 1,000 meters are equal to one kilometer.

One advantage of the metric scale is that it is easier for users to perform calculations. For instance, you can easily accomplish the conversion of kilometers to meters when you divide by 1,000. In the United States, when you convert miles to feet, you have to divide by 5,280. Not only is this conversion factor more difficult to remember, but the conversion often requires a calculator. United States scientists and engineers use the metric system, just as scientists and engineers in other parts of the world use the metric system and not the English system.