Selling metres

Hello Im using opencart in version 2.1.0.2.
I have a question, how I can selling products by metres ?
If customer want to buy a product which price is by 1 metre how he can buy fe. 3,2 m ?
When customer type 3,2 m the price should be calculated.

The probably ONLY Extension, exactly matching your requirements, is only OC v.1.5.x,
but others could made to work as well, I assume, with more or less limitations, and work involved.

PPM (Price per meters & square meters) OC v.1.5. - 1.5.6.4 paid
http://www.opencart.com/index.php?route ... on_id=7214

Unit Of Measurement OC v.1.5.4 - 2.x paid
http://www.opencart.com/index.php?route ... n_id=20545

price by formula OC v.1.5.4 - 2.1.0.2 paid
http://www.opencart.com/index.php?route ... n_id=22281

Size option type OC v.2.0.1 free
http://www.opencart.com/index.php?route ... n_id=20617

Product Size Option OC v.1.5 - 2.2 paid
http://www.opencart.com/index.php?route ... n_id=12993

Shop by Size OC v.1.5. - 2.1.0.2 paid
http://www.opencart.com/index.php?route ... on_id=3041

Product Custom Size Option OC v.2.0.1 - 2.1.0.2 paid
http://www.opencart.com/index.php?route ... n_id=23568

Custom Size option 2.0 OC v.1.5 - 2.1.0.2 paid
http://www.opencart.com/index.php?route ... n_id=15755

More can possibly be found here:
http://www.opencart.com/index.php?route ... er%20meter

Good Luck
Ernie
openshop.li