Mamas and papas do use standard sizes but to make sure you buy their mattresses they make their measurements a tiny bit smaller than standard
M&P cot size 400 ( 139 x 69cm ) fits a standard cot mattress 140 x 70cm M&P cot size 200 ( 120 x 60cm ) fits a standard cot mattress 120 x 60cm M&P cot mattress 300 (126 x 62.5cm ) fits common mattress sizes sold such as 126 x 63cm and 127 x 64cm
I know you said you wanted to go to M&P for the matress, but jsut incase you're happy to consider alternatives, we bought a M&P cot but I didn't want to get one of thier matresses as they were so over priced. Dispite M&P cots being slightly odd sizes (presumably so they can make you buy thier matresses!) we got one the correct size from amazon. It was a proper sprung one with a removable washable outer and only about £35 - bargin! I just googled the M&P size that was suggested and found something that told me what the actual measurements were so I could then find a matress of that size. Shame none of the regular sheets seem to fit though!
yeah I think m&p sizes are a bit odd. I would go in for advice but I never quite trust them (they're a bit useless in my branch) and think they just recommend the one they want to shift. Thought it might be useful to get actual accounts from people who have used them to see which models are recommended by 'real mums' if any.
Do Mamas and Pappas make weird-sized cots so that you have to buy their mattresses? If so, have you gone into a M&P store to ask for advice? If you're really stuck, you might just need to order the closest size and try it in the cot. If you don't take off any of the packaging, you can return it as unused if it doesn't fit. If you take off the pacakaging, you will find it really hard to take back.
Otherwise, have a hunt around other manufacturers' websites as they might have a closer match.
As long as the gap between the mattress and the side of the cot doesn't exceed 4cm at any point it will be fine.
Sorry if that is all really obvious, just saying what I would do.
We are thoroughly confused and not sure which one to go for. We have the cot from m&p (second hand) and want to go to m&p to mattress only as the cot is a few years old and, although m&p claim the mattress/cot sizes haven't ever changed, their measurements just don't quite seem to fit the cot, so at least if we stick with m&p they can't complain if we need to return etc.
Anyone used any mattresses from m&p and would recommend/avoid their specific model? We want one to last the full way with our LO so needs a good 2 or so years life from it and we need to get a size 300 if that means anything to you.