Wrench sizes are a bit easier to figure out than socket sizes since you are not dealing with different ratchet drive sizes. While the average fixed wrench set or ratcheting wrench set won’t include every single size of wrench, you’ll likely only use a few of them depending on the general use.
A car mechanic will use a large range of wrench sizes while someone who works on bicycles or farming equipment may only use a small number of sizes.
Here are Standard (SAE) and Metric wrench sizes (from smallest to largest) that can often be found as part of a set or individually.
Related: Hex Key Sizes (Conversion Chart)
Note: Along with each size is the decimal equivalent (in inches) so you can compare applies to apples when trying to determine if a metric size wrench is close enough to its SAE equivalent (and vice versa).
CLICK HERE to download charts as a PDF
Wrench Size Conversion Chart (SAE to Metric)
| SAE Size | Metric Size | Inches Decimal | Note |
|---|---|---|---|
| 5/32" | 0.156 | 5/32" and 4mm are close enough | |
| 4mm | 0.157 | ||
| 4.5mm | 0.177 | ||
| 3/16" | 0.188 | ||
| 5mm | 0.197 | ||
| 5.5mm | 0.216 | ||
| 7/32" | 0.219 | ||
| 6mm | 0.236 | ||
| 1/4" | 0.250 | ||
| 6.5mm | 0.256 | ||
| 7mm | 0.276 | ||
| 9/32" | 0.281 | ||
| 5/16" | 0.313 | 5/16" and 8mm are close enough | |
| 8mm | 0.315 | ||
| 11/32" | 0.344 | ||
| 9mm | 0.354 | ||
| 3/8" | 0.375 | ||
| 10mm | 0.394 | ||
| 13/32" | 0.406 | ||
| 11mm | 0.433 | 7/16" and 11mm are close enough | |
| 7/16" | 0.438 | ||
| 15/32" | 0.469 | 15/32" and 12mm are close enough | |
| 12mm | 0.472 | ||
| 1/2" | 0.500 | ||
| 13mm | 0.512 | ||
| 17/32" | 0.531 | ||
| 14mm | 0.551 | ||
| 9/16" | 0.563 | ||
| 15mm | 0.591 | 19/32" and 15mm are close enough | |
| 19/32" | 0.594 | ||
| 5/8" | 0.625 | 5/8" and 16mm are close enough | |
| 16mm | 0.630 | ||
| 21/32" | 0.656 | ||
| 17mm | 0.669 | ||
| 11/16" | 0.688 | ||
| 18mm | 0.709 | ||
| 23/32" | 0.719 | ||
| 19mm | 0.748 | 3/4" and 19mm are close enough | |
| 3/4" | 0.750 | ||
| 25/32" | 0.781 | ||
| 20mm | 0.787 | ||
| 13/16" | 0.813 | ||
| 21mm | 0.827 | ||
| 27/32" | 0.844 | ||
| 22mm | 0.866 | ||
| 7/8" | 0.875 | ||
| 23mm | 0.906 | 29/32" and 23mm are close enough | |
| 29/32" | 0.906 | ||
| 15/16" | 0.938 | ||
| 24mm | 0.945 | ||
| 25mm | 0.984 | ||
| 1" | 1.000 | ||
| 26mm | 1.024 | ||
| 1-1/16" | 1.063 | 1-1/16" and 27mm are close enough | |
| 27mm | 1.063 | ||
| 28mm | 1.102 | ||
| 1-1/8" | 1.125 | ||
| 29mm | 1.142 | ||
| 30mm | 1.181 | ||
| 1-3/16" | 1.188 | ||
| 31mm | 1.221 | ||
| 1-1/4" | 1.250 | 1-1/4" and 32mm are close enough | |
| 32mm | 1.256 | ||
| 33mm | 1.299 | ||
| 1-5/16" | 1.313 | ||
| 34mm | 1.339 | ||
| 1-3/8" | 1.375 | 1-3/8" and 35mm are close enough | |
| 35mm | 1.378 | ||
| 36mm | 1.417 | ||
| 1-7/16" | 1.438 | ||
| 37mm | 1.457 | ||
| 38mm | 1.496 | 1-1/2" and 38mm are close enough | |
| 1-1/2" | 1.500 | ||
| 39mm | 1.535 | ||
| 40mm | 1.575 | ||
| 41mm | 1.614 | ||
| 1-5/8" | 1.625 | ||
| 42mm | 1.654 | ||
| 1-11/16" | 1.688 | 1-11/16" and 43mm are close enough | |
| 43mm | 1.693 | ||
| 44mm | 1.733 | ||
| 1-3/4" | 1.750 | ||
| 45mm | 1.772 | ||
| 46mm | 1.811 | ||
| 1-13/16" | 1.813 | ||
| 47mm | 1.850 | ||
| 1-7/8" | 1.875 | ||
| 48mm | 1.890 | ||
| 49mm | 1.923 | ||
| 50mm | 1.969 | ||
| 2" | 2.000 | 2" and 51mm are close enough | |
| 51mm | 2.008 | ||
| 52mm | 2.047 | ||
| 2-1/16" | 2.063 | ||
| 53mm | 2.087 | ||
| 2-1/8" | 2.125 | 2-1/8" and 54mm are close enough | |
| 54mm | 2.126 | ||
| 55mm | 2.165 | ||
| 2-3/16" | 2.188 | ||
| 56mm | 2.205 | ||
| 57mm | 2.244 | 2-1/4" and 57mm are close enough | |
| 2-1/4" | 2.250 | ||
| 58mm | 2.283 | ||
| 59mm | 2.323 | ||
| 60mm | 2.362 | ||
| 2-3/8" | 2.375 | ||
| 61mm | 2.402 | ||
| 62mm | 2.441 | ||
| 63mm | 2.480 | ||
| 2-1/2" | 2.500 |
Need to know what wrench size you’ll need for a specific diameter of bolt or nut? We’ve got you covered.
Related: 6 vs 12-Point Sockets (Common Uses)
Wrench Size Chart for Bolts
| Bolt Diameter | Wrench Size (Standard) | Wrench Size (Metric) |
|---|---|---|
| 1/8" | 5/16" | 8mm |
| 3/16" | 3/8" | 10mm |
| 1/4" | 7/16" | 11mm |
| 5/16" | 1/2" | 13mm |
| 3/8" | 9/16" | 15mm |
| 7/16" | 5/8" | 16mm |
| 1/2" | 3/4" | 19mm |
| 9/16" | 13/16" | 21mm |
| 5/8" | 15/16" | 24mm |
| 3/4" | 1-1/8" | 29mm |
| 7/8" | 1-5/16" | 34mm |
| 1" | 1-1/2" | 38mm |
| 1-1/8" | 1-11/16" | 43mm |
| 1-1/4" | 1-7/8" | 48mm |
| 1-3/8" | 2-1/16" | 53mm |
| 1-1/2" | 2-1/4" | 58mm |
| 1-5/8" | 2-7/16" | 62mm |
| 1-3/4" | 2-5/8" | 67mm |
| 1-7/8" | 2-13/16" | 72mm |
| 2" | 3" | 77mm |
| 2-1/4" | 3-3/8" | 86mm |
| 2-1/2" | 3-3/4" | 96mm |
| 2-3/4" | 4-1/8" | 105mm |
| 3" | 4-1/2" | 115mm |
See Also: Hole Saw Sizes Chart
you should make another list like this for screwdrivers
Good idea. I’ll definitely add this to the queue.
there are thick nuts, thin nuts, wide nuts, etc. the wrench sizes here aren’t necessarily accurate.
Ty for doing it and standard and what metric it equals to makes it more convenient when I’m organizing my big wrenches on the wall I can put the standard wrench than the metric wrench right below it very helpful
Great charts they are very helpful thank you.
Thank you so much for doing these charts. Multiple concussions have made my brain into mush.
I used to help my father and assorted grease monkey friends work on their cars, bikes etc. And I know that I am extremely OCD about keeping my tools in order. My father taught me that.
* NOTE- Never ever lend out your tools. If you’re lucky enough to get them back, they will be trashed.
Mine were recently returned after over a month in a large zip lock bag. Somehow the person managed to lose a few. I know, that happens. Oh well. C’est la vie. But how’d they lose my holder’s is beyond my understanding?
Your chart has been a phenomenal help today as I attempt to clean and reorganize my socket sets. I wish that the part of my brain that used to be able to figure out the sizes would be with me still.
Obviously you have it. Again, thank you.
Glad these were helpful. I have a little OCD in me as well. Can’t remember how many different chart formats I tried before deciding on the ones here (and I still wonder if there’s a better way of doing them!). I agree about your rule on lending out tools but over time, you tend to accumulate duplicates of certain tools which definitely helps. 🙂
I am a woman that just lost her husband. I have all these wrenches and sockets that I do not know what size from another this site was a great tool for me and I will pass it on to other ladies
Thanks Bonnie. I’m so sorry for your loss.
Same for me too! My husband was a mechanic who passed, and I have so many tools. So I am now decreasing them and putting it in order to sell. This chart has been an extream help. Thank you!
Bonnie Wilson,
More and more Women have become DIY’ers, and they understand repair work quite easily. I hope that you put those tools to good use. I am very sorry for your loss.
Note; There are many “How To” videos on youtube. Try to learn from them. It’s easy, once you’ve seen others do it. (many of those videos, are by Women) Good Luck to you!
Kind Regards,
Joe Prete
Can you please update the chart to include 4.5, 5.5, 6.5mm? I know these are not as common anymore but I do have a few old sets with them. Along with some bold /32” mini wrenches that your chart is missing. A downloadable pdf of this cart would be great if you could provide it also! Thanks!
That’s a good idea. I’ll put it in the queue.
I never see 1 3/16” and 30mm…
I have several
I special order them. I don’t know why they don’t stock them.
I love these charts. A have had to fin for myself for a long while now doing things that I never had to do. Learning all about tools and such. This is a great help. Thanks.
i dont know what YOU use wrenches on, but I work on anything automotive and one thing is for sure … 14mm and 9/16″ are unmistakebly identical and this you do not recognize in ur charts ?? Others are comparebly close
Good comment. I didn’t include 14mm and 9/16″ as a good conversion since they’re far enough apart where one tool brand may work while another will be too tight/loose due to a tolerance difference. I’m sure I’ve used one over the other at some point when in a pinch but the size difference is a bit too much to recommend as a “close enough” recommendation.
Very helpful chart. I have very many wrenches and sockets that have been collected over the past 50 years, mine, my fathers, my brothers and who knows who elses. They’ve been thrown together in different containers over the years, but now I am going to build an organizer for them so they can be arranged in size order. This will make my looking for tool sizes a lot easier. Thanks for this chart, I’ll use it to arrange the tools.
I know it also matters on the sockets if its as 6 point or 12 point rather it’s a metric or standard on if its gonna fit snug or not. Plus also, is it well used socket or wrench or if its fairly new. The more it’s used the less chance of it bring snug.
The place where I worked was mostly standard sized but the newer equipment was coming in as metric so I added the following metric sizes to fill in the holes in my sets.
6mm, 10mm, 13mm, 16mm, 18mm, 21mm and 24mm. These sizes really don’t have standard equivalents and with this I had 1 set to rule them all.
1-1/2″ is close enough to 38mm, and 2″ is close enough to 51mm, not 52mm
Good catch! Thanks. Fixed.
Why no 1-3/16?
Not sure how I missed that. Thanks Dan. Fixed.
This is a very helpful website, it has helped me to organize a put together all the sockets and wrenches together by drive and socket, and size. Now my dad won’t have to go digging around in the tool box looking for the right size socket and driver. Very helpful thanks for the information. It’s people like this that makes my life a whole lot more simple.
Thanks Jeffrey. Glad you found it useful.
What size works for an adult or kid’s bike wheel?
15mm is by far the most common but some manufacturers use 13mm, 14mm, or 17mm.
Is there a term for the size ranges, say 1/4″ through 1″ as “standard” an 1-1/16 up to (?) as “Large”. Wrench manufacturers don’t seem to differentiate.
My son is a Millwright an I’d like to get him a complet-ish set for Christmas.
There’s no standard classification for size ranges. It might be a good idea to check out a few millwright “tool list” recommendations and go from there. Here’s a good one depending on his level: https://www.sectt.net/pdf/1c15n14sj_557445.pdf
Here are some wrench sets and socket sets we recommend.