🔩 Nut & Fastener Calculator
Calculate exactly how many nuts, bolts, washers, and fasteners you need for any project
| Nut Size (Imperial) | Thread (TPI) | Width Across Flats | Metric Equiv. | Common Grade |
|---|---|---|---|---|
| 1/4"-20 | 20 TPI | 7/16" (11.1mm) | M6 | Grade 2 / Grade 5 |
| 5/16"-18 | 18 TPI | 1/2" (12.7mm) | M8 | Grade 2 / Grade 5 |
| 3/8"-16 | 16 TPI | 9/16" (14.3mm) | M10 | Grade 5 / Grade 8 |
| 7/16"-14 | 14 TPI | 11/16" (17.5mm) | M11 | Grade 5 / Grade 8 |
| 1/2"-13 | 13 TPI | 3/4" (19.1mm) | M12 | Grade 5 / Grade 8 |
| 5/8"-11 | 11 TPI | 15/16" (23.8mm) | M16 | Grade 8 |
| 3/4"-10 | 10 TPI | 1-1/8" (28.6mm) | M20 | Grade 8 |
| 1"-8 | 8 TPI | 1-1/2" (38.1mm) | M24 | Grade 8 |
| Metric Size | Pitch (mm) | Width Across Flats | Imperial Equiv. | DIN Standard |
|---|---|---|---|---|
| M4 | 0.70mm | 7mm | #8–32 | DIN 934 |
| M5 | 0.80mm | 8mm | #10–24 | DIN 934 |
| M6 | 1.00mm | 10mm | 1/4"-20 | DIN 934 |
| M8 | 1.25mm | 13mm | 5/16"-18 | DIN 934 |
| M10 | 1.50mm | 17mm | 3/8"-16 | DIN 934 |
| M12 | 1.75mm | 19mm | 1/2"-13 | DIN 934 |
| M16 | 2.00mm | 24mm | 5/8"-11 | DIN 934 |
| M20 | 2.50mm | 30mm | 3/4"-10 | DIN 934 |
| Nut Size | Pcs per Pound | Typical Pkg Size | Pcs per kg |
|---|---|---|---|
| 1/4" Hex | ~350 pcs/lb | 100 or 500 pcs | ~770 pcs/kg |
| 5/16" Hex | ~170 pcs/lb | 50 or 100 pcs | ~375 pcs/kg |
| 3/8" Hex | ~95 pcs/lb | 50 or 100 pcs | ~210 pcs/kg |
| 1/2" Hex | ~42 pcs/lb | 25 or 50 pcs | ~93 pcs/kg |
| 5/8" Hex | ~22 pcs/lb | 25 pcs | ~49 pcs/kg |
| 3/4" Hex | ~12 pcs/lb | 10 or 25 pcs | ~26 pcs/kg |
| M6 Hex | — | 100 or 500 pcs | ~1,250 pcs/kg |
| M8 Hex | — | 50 or 200 pcs | ~530 pcs/kg |
| M10 Hex | — | 50 or 100 pcs | ~265 pcs/kg |
| M12 Hex | — | 25 or 100 pcs | ~130 pcs/kg |
| Project | Fastening Points | Recommended Size | Total Nuts Needed |
|---|---|---|---|
| Deck 10×16 ft | ~80 bolts | 3/8" or 1/2" | ~90 (with 10% buffer) |
| 6-ft Privacy Fence (50 panels) | ~100 bolts | 5/16" | ~110 (with 10% buffer) |
| Steel Carport Frame | ~60 bolts | 1/2" or M12 | ~132 (double-nut + buffer) |
| Wood Pergola | ~40 bolts | 5/8" | ~44 (with 10% buffer) |
| Metal Shelving Unit | ~32 bolts | 1/4" or M6 | ~36 (with 10% buffer) |
| Engine / Machinery Bracket | ~12 bolts | M10 or 3/8" | ~26 (double-nut + buffer) |
Add at least 10% extra to your nut count. Nuts are inexpensive but running short mid-project wastes time. For critical structural work, use 15–20% overage and store spares for future repairs.
For vibration-prone applications (engines, vehicles, heavy machinery), use two nuts per bolt – tighten the inner nut first, then tighten the outer nut against it. This method is reliable and does not require special lock nuts.
When building a construction projects, you must plan for the number of nuts you will need. If you find that you dont have enough nut for the number of fastening point on your project, your construction project will be delayed. You must consider the number of nuts you need for each fastening point.
In some instances, there may be a need for more than one nut at a fastening point. For example, if the machinery that you are building requires two nut to fasten secure, you will have to double the number of nuts that you count at these points. Additionally, you will have to account for the number of washers and extra nut that you will need.
How to Count and Buy the Right Nuts for Your Project
Washers will help to evenly distribute the force of the nuts on the object, and you may also have to include extra nuts in case you encounter issues with dropping or stripping an nut. The thread pitch for the nuts is another specification you need to consider when building your project. The thread pitch for the nut must match that of the bolt.
For example, a 3/8-inch bolt will have 16 thread per inch, so the nut will also need to have 16 threads per inch. If the thread pitches for the nut and bolt do not match, the nut will not fit the bolt. For applications where the materials being fastened together are relatively soft, such as wood, coarse thread are used.
For metalwork, users use fine threads so that they provide for more precision in positioning. The thread pitch of the nut must match the thread pitch of the bolt. Additionally, the size of the nut must match the bolt size.
The weight of nuts and the number of nuts of a specific size vary. Small nuts of 1/4 inch in size are available in large quantity of around 350 nuts per pound. Because of this, purchasing nuts of these sizes in bulk is a cost-effective method of acquiring the nuts you need for your projects.
However, nuts that are 1/2 inches in size weigh more and there are fewer of these nuts per pound, so they are available in smaller quantities. It is best to purchase nuts in boxes of 50, 100, or 250 nuts. You should purchase these packages in quantities that account for the total number of nuts you will need; any number below the total quantity should of be rounded up to the next package size.
Purchasing nuts with a 10 percent buffer between your estimated and actual need will ensure that you have enough nuts to account for mistakes you may make while using them. Another important factor to consider is the material of the nuts. If the construction project is exposed to the elements, nuts made of stainless steel will resist rust.
Steel nuts are used for projects that require high strength, such as structural builds. Additionally, projects that experience high vibration, such as engine, use nylon-insert lock nuts. Flange nuts are used for projects where you also need to incorporate a washer.
The weight of the nuts is another factor to consider. If the nuts are too heavy for the load that you will transport them with, you will encounter difficulties in moving the nuts to your project. Therefore, you should avoid underestimating the weight of nuts.
To determine the number of nuts you need for your project, first sketch out the frame of your construction project. Count every fastening point that the nuts will secure. For example, a 10-by-20-foot section of a deck may have 80 fastening points.
These fastening points will require one nut and two washers each, so there will be 80 nuts and 160 washers needed for this example of a construction project. If the project also require double-nutting, you will need to double the number of nuts required. Additionally, the grade of the nut should match the grade of the bolt.
For high-stress imperial bolts, the grade of the nut should be 5 or 8. For metric bolts, class 8 nut should be used. Double-nutting is used for securing nuts into projects that experience vibration.
To double-nut, first fully tighten the bottom nut. Then, add a second nut and fully tighten it against the first nut. This will prevent vibration from loosening the nuts.
Additionally, by adding washers to these nuts, you can help distribute the force of the nuts on the object being fastened. To prepare for your construction project, store any extra nuts that you do not need for the project in labeled bins according to the size of the nuts. This will make finding the correct size of nut for your future repair projects more easy.
You’ll find that its much more simple than it looks. Most people dont realize how alot of small parts can dissapear. When you are working with moddern hardware, you should of double checked the dimensions.
It is actualy quite simple if you follows the steps.
