Choose a profile and calculate the belt length

When designing a new system there is always a challenge when it comes to make a decision as of what kind of belt should be used and how to calculate the length and choose the pulleys.

I recently discover a program, and thanks to a customer I was helping at the moment. It’s called MITCalc. I usually do my designs the old fashion, interesting way to do the complete calculation, but this is definitely an easier way to do it.

This application is FREE for 3 days and then you can buy it for a very low price (less than $20.00). Go to this website and look for V-belts under the Standalone calculations for Excel. Click download, select the language and follow the prompts for installation and click finish.

(We have no relation with this website or its owners, but we have use the application and it’s accurate and easy to use.)

Once you install it, look for the file MITCalc on your program files, open the vbelts file and then open vbelt_02 for metric belts, or vbeltin_02 for belts in inches. This will open an excel document, which is the one you will use for your calculations. Click demo if you are using the unpaid version.

v-belt length calculation

Click + on 3 pulleys or 2 pulleys, according to the system that you have

Fill in the fields in white and click automatic design. Go to the drawings and select the type of belt with the values in 5.1 and 5.2 (use the higher rpm/min)

v-belt selection

If you see, with 35 KW and 1500 rmp/min, which are the numbers we used, we need to go to #2 and the belt that we need is the SPA

v-belt graphic selection


On number 6.2 select the belt type you got from the drawing 2. In this case, it is the SPA belt

v-belt selection results

Click Optim and voila…. There it is, item 6.6 is the length of the belt you need, and number 6.10 number of belts for this specific system.

So we need 4 pieces of the SPA belt 2650 mm long.

You can repeat the same process for belts in inches and see which one adjust better to your design, space, requirements and availability

If you need more information or need help selecting the v-belt you need, please leave us a comment and we will be happy to help