PD Ruler: Free download

Download your free PD ruler.


Aerial view of free PD ruler on blue background

How can I measure my PD for free?

The easiest way to measure your PD for free is to use this downloadable PDF ruler. Unlike a regular ruler, it features a V-slot for your nose which centres and steadies itself - making it simple and easy to use. Better still, it features mirror-friendly numbers which are reversed so you can read them more easily.


Can I measure my PD with a ruler?

Yes, you can use a regular stationery ruler to measure your PD, as long as it has mm increments. This method requires a steady hand to hold the ruler level and still to attain an accurate measurement. To make it easier, it's a good idea to ask for assistance. Alternatively, you can use a our free PD ruler.


Can I measure my PD with my phone?

Yes, there are various online apps which you can download and use to digitally measure your PD. EyeMeasure offer a fantastic tool which is reliable and accurate for attaining your pupillary distance.


Where is my PD on prescription? 

Your prescription may or may not feature your pupillary distance. This measurement isn't mandatory, therefore opticians aren’t obligated to provide this as part of your eye exam results. This can make things a little awkward when you realise, you’ll have to ask for it.

In other words, your request for your PD will go down like a lead balloon with your optician. Basically, it’s code for; “I’d rather buy my glasses from somewhere else.”

"Lots of optometrists will give you a copy of your prescription but not include your PD. That’s because they know that, armed with both, you can order your glasses online."


To avoid any awkward confrontation, you can measure your PD yourself using our free PD ruler. It’s downloadable, easy to make and gives an accurate measurement.

White PD ruler being used to measure persons eyes

What is a PD ruler?

A PD ruler is similar to a regular ruler that’s been modified to locate on your nose. Just like a pair of glasses, there’s a handy V shaped slot that mimics how your glasses rest on your face. This little slot makes it super easy to find the middle of your face. (zero)

Using millimetre increments, your free PD ruler lets you measure the precise distance between your pupils. This is perfect for measuring both your single or dual PD measurements without having to request it from your optician.


The difference between single PD and Dual PD

What is single PD? 

Single PD is the single total distance between your pupils. This measurement is generally required for lesser prescription such as single vision, prescription reading glasses or computer glasses.


What is dual PD?

Dual PD is two separate measurements, noting the distance from the centre of each pupil to the centre of your head. Also known as monocular PD, these individual figures are used for more intricate prescriptions that require greater accuracy.


Illustration of dual PD measurement

Should dual PD's match?

No. Dual PD's intentionally cater for facial asymmetry (very common) which makes it a superior option over single PD measurements. For example, if you've experienced a broken nose, a dual PD caters for non-equidistant alignment of your frame on your face.

If you have two different numbers for your dual PD, you're not alone. This imbalance is perfectly normal and means that the optical centres of your new lenses will need to be slightly different.


How accurate does my PD need to be?

Attaining an accurate PD is important for aligning your pupils behind the optical centres of your new lenses. This is why millimetres are used to establish precision. However, don't get caught in weeds thinking a slight deviation will render your glasses useless. A few mm here or there is fine. 

To make things easy for yourself and avoid mistakes, download your free PD ruler. Using the in-built V slot for your nose, you can easily measure your dual pupillary distance yourself.


White measuring tape on blue paper background

What is the average PD for a woman?

  • Single PD: 62mm
  • Dual PD: 31mm

What is the average PD for a man?

  • Single PD: 64mm
  • Dual PD: 32mm


Average PD’s can be used if you have a mild prescriptions or if you can't provide one. If you wear single vision lenses with a strength of less +/-4.00 you can get away with using the average PD measurements as listed above.

However, if you have a particularly large or small head, we recommend that you don’t use average PD sizes to save any issues with your new lenses.

Hopefully you found this article helpful. Please check out our other eyecare blogs. Thanks for stopping by.

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