Hi Paul, 

Thanks for your question. 
 
This will differ between retailers as the fillings in the mattress, being different, will have different weights. 
 
Please see below for our guidelines on our own products;
 

 
Is there a particular model you're looking at as we do have 4 different mattress ranges; We have our Origins and Artisan ranges that are traditional pocket sprung mattresses. Pocket sprung mattresses give you support from the spring within and you then have the comfort from the fillings.
 
We then have our Hybrid Foam and Fusion (100% Natural Latex) ranges. These give sink in sensations similar to memory foam but without the heat issues associated. These ranges are great for pressure relief. 
 

 
Please don't hesitate to come back to us at your earliest convenience to discuss this further on 0161 437 4419. We are open Monday to Friday 8am to 8pm and Saturday and Sunday 10am to 4pm. 
 
Kind Regards, Lee.