I’ve filled the cups with water to test them out – filling to just touching the bottom of the airholes, and level with the top of the rim. I couldn’t test this accurately with the Keeper as the sample I have has a HUGE hole in it, but I covered it with plastic wrap and tried my best.
Size 1 Diva – 20ml to airholes, 29mls to the rim
Size B Mooncup – 12mls to airholes, 25mls to the rim
Size A Mooncup – 14mls to airholes, 28mls to the rim
Size 2 Lunette – 26mls to the airholes, 34mls to rim.
Size B Keeper – 12mls to the airholes, 20mls to rim?
The Kukuppi site gives slightly different measurements for Diva, Lunette & Mooncup:
Size 1 Diva – 20ml
Size 2 Diva – 25ml
Size B Mooncup – 13mls
Size A Mooncup – 15mls
Size 2 Lunette – 20mls
Size 2 Lunette – 24mls
Measuring the accuracy of the measuring lines.
Most of the cups have measuring lines on the side. Out of curiosity I tried pouring water in to see if they were correct according to my measuring devices (a medicine cup and an eyedropper with ml markings). Interestingly… my measuring cups and dropper give a different result to the lines…… I checked my measuring cups against eachother (and a second medicine cup of a different variety), and they appear to be correct (as much as I can tell with 1ml increments). The Femmecup, Diva and Lunette measurements were done on the same day with the same measuring cups/dropper. The Mooncup measurements were done on a different day but with the same measuring cups/dropper. These are approximates only, as my measuring implements are rather less than precise.
Mooncup B has a 12ml mark that my measuring cups said was at 10mls.
Mooncup A has a 15ml mark that my measuring cups said was at 12mls.
Femmecup has a 15ml mark, which my measuring cups said was at 12mls
Lunette’s lines are unmarked, but the top mark is believed to be 15mls, but was 17mls by my measure.
Diva’s 15ml mark was 15mls by my measuring cups.
While the Lunette, Diva and Mooncup samples have a hole punched in them – this hole is higher than the measuring lines, so cannot have any impact on the results. I was also of course careful not to squeeze the cups too firmly when holding them, so as not to reduce their volume. I do not know why the results vary… particularly since the 3 cups measured on the one day, Femmecup, Diva and Lunette have both a matching, higher and lower result. Most of these I tested in both a dry state and with still a few drops of water in from a previous test (which didn’t appear to change the results)
Now I will state here that I’m not a trained measurer or anything and while I’ve tried to check my measuring implements against each other, and tried to hold the cups exactly level and get the volumes as accurate as possible, I don’t believe my results to be completely accurate… with my measuring cups only marking full mls (and me being too lazy to do it with the eyedropper that does 1/4mls)…. and the fact that when measuring water it’s sometimes difficult to get exactly accurate measurements if you want to be more precise than down to 1ml………. so it’s likely that these results are up to 1ml off…. I expect its more likely to be around 1/2ml off… but I’m willing to accept it being a full ml difference. So for example, while I have said that Femmecup was 12mls, it could easily be 11mls or 13mls. I would find it hard to believe however that my measurements could be 2-3mls off though… that’s actually a fair amount of liquid…… and the Diva measurement matched the markings the first time I checked it (and as with all the measurements, I did check more than once), and I measured it at the same time I measured Femmecup and Lunette – which have different results. But I find it unlikely that all the menstrual cups would have markings at incorrect levels…. or why 3 measuring devices I have, all different brands and shapes, would be all inaccurate to the same level (eg that 2 medicine cups and an eyedropper all actually hold 2mls of water when their measuring lines say 1ml) So I have no idea why the measurement lines don’t match my findings….