# Source: https://learn.adafruit.com/calipers/step-and-relative-measurements.md

# Calipers

## Step & Relative Measurements

Say we have a mint tin that we're measuring. We want to know the thickness of the metal, but because of the rolled edges, there's no easy way for us get a good measurement with the outer-pincers. However, we can use two measurements and subtract them! This is what digital calipers are good at.

Step measurements are taken by pressing the 'head' against the bottom of the tin and then lining up the offset movable side so that it presses against the top of the edge.

![](https://cdn-learn.adafruit.com/assets/assets/000/000/858/medium800/hand_tools_insidedepth.jpg?1396766477)

Now zero out the measurement.![](https://cdn-learn.adafruit.com/assets/assets/000/000/859/medium800/hand_tools_zerothickness.jpg?1396766488)

And measure the overall thickness. The difference is the thickness of the bottom metal.![](https://cdn-learn.adafruit.com/assets/assets/000/000/860/medium800/hand_tools_thickness.jpg?1396766493)

This measurement came out to 33.5 mils.&nbsp;[The closest standard sheet gauge](http://www.engineersedge.com/gauge.htm)&nbsp;to 0.0335 is 20 gauge. Variations in the metal thickness may be due to additional thickness from the plating process or the rounded edges interfering with the depth measurement. Taking multiple measurements is always a good idea!- [Previous Page](https://learn.adafruit.com/calipers/basic-measurements.md)
- [Next Page](https://learn.adafruit.com/calipers/other-measuring-tips.md)

## Featured Products

### Mitutoyo - Absolute Digimatic Digital Calipers, 6 in.

[Mitutoyo - Absolute Digimatic Digital Calipers, 6 in.](https://www.adafruit.com/product/294)
The most useful tool we've ever laid our hands on. &nbsp;We thought we'd use them just for electronics but then we got our hands on these calipers and had so much fun we started measuring&nbsp;_everything._

They're indestructible - which is good because we don't...

No Longer Stocked
[Buy Now](https://www.adafruit.com/product/294)
[Related Guides to the Product](https://learn.adafruit.com/products/294/guides)
### Premium Digital Stainless Steel Calipers

[Premium Digital Stainless Steel Calipers](https://www.adafruit.com/product/1724)
The most useful tool we've ever laid our hands on. These calipers are really good quality and an excellent choice if you need something better than a cheap 'disposable' pair of digital calipers but you're not quite ready for a set of high-end Mitsutoyo calipers. These digital...

No Longer Stocked
[Buy Now](https://www.adafruit.com/product/1724)
[Related Guides to the Product](https://learn.adafruit.com/products/1724/guides)
### Solar Digital Calipers

[Solar Digital Calipers](https://www.adafruit.com/product/3720)
_Praise the sun!_ You will never have that awkward situation where your caliper battery dies just when you need to take a measurement. Sure, if you have the budget, [we recommend these near-indestructible high-end Mitutoyo...](https://www.adafruit.com/product/294)

In Stock
[Buy Now](https://www.adafruit.com/product/3720)
[Related Guides to the Product](https://learn.adafruit.com/products/3720/guides)
### Messograf Pen Calipers

[Messograf Pen Calipers](https://www.adafruit.com/product/810)
Discontinued - **you can grab [Solar Digital Calipers&nbsp;](https://www.adafruit.com/product/3720)instead!&nbsp;**

&nbsp;

Caliper rule? Tire tread gauge? Ruler? Thread scale? Writing instrument? The Messograf is all of these in one.  
  
It is a...

No Longer Stocked
[Buy Now](https://www.adafruit.com/product/810)
[Related Guides to the Product](https://learn.adafruit.com/products/810/guides)

## Related Guides

- [Secret Hollow Book Intrusion Detector](https://learn.adafruit.com/secret-hollow-book.md)
- [Necomimi Brainwave Cat Ears Teardown](https://learn.adafruit.com/necomimi-brainwave-cat-ears-teardown.md)
- [Ambient Sound Machine](https://learn.adafruit.com/ambient-machine.md)
- [Personal Torch 3000](https://learn.adafruit.com/pt3000-personal-torch.md)
- [Butterfly Bench with Edge Lit Acrylic](https://learn.adafruit.com/butterfly-bench-with-edge-lit-acrylic.md)
- [Bass MIDI Stomp Box](https://learn.adafruit.com/midi-bass-synth-stomp-box.md)
- [Build a Custom Front Panel](https://learn.adafruit.com/build-a-custom-front-panel.md)
- [Collin's Lab: Soldering](https://learn.adafruit.com/collins-lab-soldering.md)
- [3D Printed Custom Keycaps](https://learn.adafruit.com/3dprinted-custom-keycaps.md)
- [Fiddy - the FTDI Clip](https://learn.adafruit.com/fiddy-ftdi-pogo-pin-clip.md)
- [Photo Light Box](https://learn.adafruit.com/photo-light-box.md)
- [DIY On/Off JST Switch Adapter](https://learn.adafruit.com/on-slash-off-switches.md)
- [Making Edge Guards for Hand Tools Using Hand-Moldable Plastic](https://learn.adafruit.com/hand-moldable-edge-guards.md)
- [USB Locket](https://learn.adafruit.com/usb-locket.md)
- [DIY 3D Printing Filament](https://learn.adafruit.com/diy-3d-printing-filament.md)