When choosing leather for a project, having the right size can matter a lot. A leather thickness gauge and measuring tools can help ensure the right materials are on hand for a great finished piece.

A leather thickness gauge is a tool used to measure the thickness of leather. The come in types that measure via template, caliper, and laser. Also, rulers, squares, and tapes are used to measure lengths of leather. These all help when planning, cutting, and marking leather goods.

So which measuring tools are truly helpful for the type of work you’re doing? You might already have some on hand; let’s take a look.

Leather Measuring Tools

A variety of tools are available to help measure leather, either raw material, or fine design pieces while working on a project. Most common are likely metal rulers that act both as a measuring edge, and a cutting edge which can be used to guide a knife. These help to measure length.

For measuring thickness, leather has been measured with gauges in different units around the world, and across industries. These refer to it by actual thickness, and by weight. In general, leather hides are natural substances so their thickness across the entire width of the hide can vary. As such, leather thickness for a single piece is often stated in ranges, such as 2 – 3 oz, or 2 mm – 2.4 mm.

OK, time to see each one and get a feel for which would be helpful to have in the leather shop.

Leather Thickness Gauge

Leather thickness gauges are tools that measure the thickness of leather. Different leather thicknesses are generally used for different products, and they are suited differently based on flexibility and heft. For example, thinner leathers for wallets, and thicker leathers for bags, tack, and boots.. It’s very helpful to know the general thickness of leather used for any project. Generally, leather thickness measurements are done in the units of irons, millimeters, and ounces.

This helps ensure uniformity of the materials used (so the overall feel of the finished product is consistent). It helps when purchasing leather so you know what to buy. It also helps when you’re shaving or skiing leather, know know you’ve reached the goal thickness.

Here’s a helpful video that demonstrates several options mentioned here:

Template Leather Thickness Gauge

Leather thickness gauges come in a few different forms. Some are flat pieces of wood or plastic (templates) with a tapered notch running into it. There are measurements noted along the notch, and depending how far the leather fits into the notch, the corresponding marking will tell it’s thickness.

Caliper Leather Thickness Gauge

Other leather thickness gauges are in caliper form. The leather is placed into the device and a metal rod is pushed down onto the leather, securing it between two points. Based on how far the rod was pushed down, the leather of the thickness is displayed. Displays can be either analog with a needle layout in analog calipers, or digital with a digital numeric layout in digital calipers.

Common leather thicknesses run from about 1oz (1/64” or .4mm) to 20oz (5/16” or 8mm). Here’s a video showing how the caliper gauges work:

Laser Leather Thickness Gauge

Laser thickness gauges are generally used in commercial tanneries. They allow the leather to pass between two fixed lasers and sensors. The lasers feed measurement data back to the computer that drives the machine, that then displays the precise measurement of the thickness of materials.

These lasers are usually temperature-stable, so not affected by the material surface temperature. They’re best when used on leather that is at room temperature, so the ratings will be consistent with most leather working and use conditions that leather crafters and workers will find at work and in the studio. Here’s a great animation demonstrating how these large, production-volume laser gauges work:

Leather Gauge Chart

Here is a leather gauge chart listing the different, common leather gauges. It also includes leather thicknesses for reference.

Leather Thickness and Weight Chart
Ounces	Inches	Inches (decimal)	Millimeters (mm)	Irons
1 oz	1/64″	0.0157	0.40	0.75
2 oz	1/32″	0.0313	0.80	1.50
3 oz	3/64″	0.0469	1.20	2.25
4 oz	1/16″	0.0625	1.60	3.00
5 oz	5/64″	0.0781	2.00	3.75
6 oz	3/32″	0.0938	2.40	4.50
7 oz	7/64″	0.1094	2.80	5.25
8 oz	1/8″	0.1250	3.20	6.00
9 oz	9/64″	0.1406	3.60	6.75
10 oz	5/32″	0.1563	4.00	7.50
11 oz	11/64″	0.1719	4.40	8.25
12 oz	3/16″	0.1875	4.80	9.00
13 oz	13/64″	0.2031	5.20	9.75
14 oz	7/32″	0.2188	5.60	10.50
15 oz	15/64″	0.2344	6.00	11.25
16 oz	1/4″	0.2500	6.40	12.00
17 oz	17/64″	0.2656	6.80	12.75
18 oz	9/32″	0.2813	7.20	13.50
19 oz	19/64″	0.2969	7.60	14.25
20 oz	5/16″	0.3125	8.00	15.00

To download a printable copy of the chart, click here. This version also includes a column that shows actual leather thickness, when printed at full size on standard 8.5″ x 11″ paper.

Non-Slip Metal Ruler

The non-slip metal ruler usually features cork on the backside, allowing it to rest on a variety of surfaces and non slide around. This is especially helpful when using it to mark long lines that should remain straight.

they’re also helpful for using as a metal guiding cutting edge, suitable for drawing a knife blade against it. If doing this, ensure the cork is thick (tall) enough to provide a stable edge when resting the knife against it so the knife stays on the cutting material, and to the side of the ruler.

Rulers/Squares

Rulers and squares are used in measuring and cutting leather. They come in many shapes and sizes (some rulers are bendable so even curves can be measured).

One thing to keep in mind when looking at rules and squares is the ability for it to help making leather cuts. Rulers with cork or non-slip bottoms keep them in place on the material being measured. This makes them useful for drawing steady lines, and also serving as a cutting edge when cutting leather.

The cutting blade can simply be run over the material, slightly pressed against the ruler to act as a guide. when used in this way, it’s important to ensure the ruler is either thick enough (thicker metal), or raised enough (on a thicker cork bottom, for example) to ensure it provides enough height to keep the blade from jumping off the material and onto the ruler.

Rulers and squares are a very common and useful group of leather working tools. Here’s a nice video showing the squares in use:

Leather L-Square

Squares, also known as l-squares, are generally an l-shaped ruler. They have a longer ruler-like side, and connected at a 90-degree right angle is another, shorter straight side. This allows for measuring and marking of corners and perpendicular lines, knowing the angle is precise.

L-squares are usually available in metal, plastic, or wood materials. They are marked in inches (imperial), millimeters (metric), or any variation of scale and units.

Leather Straight Edge Ruler

Rulers are generally straight, approximately 12” – 36” long, and made of metal, wood, or plastic. Measurement markings are either printed or etched along their length and can be in inches (imperial), millimeters (metric), or any variation of scale and units.

Some rulers have a metal edge built in to serve as a durable edge for running a pen or pencil against while marking material.

Tape Measure

A tape measure is a common type of measuring device that often retracts into a rolled case. They are generally made with bendable metal “blade” that has the measurements printed on it. When pulled from the case, the blade extends out and can be held next to or on top of materials to determine their size. Measurement markings can also be made based on the measurements they provide.

When done making measurements, the blade can be retracted back into the case, making for convenient carry and storage. Tape measures are usually available in inches (imperial), millimeters (metric), or any variation of scale and units. They are also available in various lengths, most often ranging from 6’ to 25’.

Leather Thickness Sample Set

Leather thickness sample sets are a group of small leather samples groups together and each marked with the specific leather thickness of the sample that it is. Different leather projects require different leather “weights” (thicknesses), it’s helpful to know which will work best.

A leather thickness sample may be comprised of 10-20, 3” x 2” pieces of leather of varying thicknesses (weights). They are usually joined with a metal ring, or a string, to neatly keep them all together. Leather thicknesses range from about 1oz (1/64” or .4mm) to 20oz (5/16” or 8mm). Being able to hold, feel, and see the specific thinnesses is quite helpful when deciding what weight material will be most useful for the work.

Measuring Tape

A measuring tape is a type of flexible distance measuring device. It is essentially a ruler printed onto a flexible material, such as plastic. This allows it to easily measure organic curves and shapes, such as people, and are often used for sewing projects.

For example measuring a waist size when making a belt or calf size when crafting leather boots. It is important that the material used does not stretch easily, either new or over time, as the accuracy of it depends on it’s ability to provide the correct measurements. Measuring tapes are usually available in inches (imperial), millimeters (metric), or any variation of scale and units.

While leather can usually be bought by thickness, sometimes it can be helpful to have a leather thickness gauge handy to check pieces while working. And the trusty ruler reigns king, a standard and loved tool in most every leather workshop. If you’d like to see my overall leather tools list, click here.

Leather Thickness Gauge and Measuring Tools – Measuring Up