Size up if you are a true to size person. I think this shoe is so sharp and dressy looking compared to other styles. The heel kept me from keeping them. Didn’t feel like it was sturdy enough for me but if you are used to wearing slimmer heels you should be fine.Finding dress pumps is a nightmare for me. I have metatarsalgia and neuromas in my long narrow feet, US 7. I got these in an EU 37. They run narrow, which is a benefit to me, but certainly will not be for people whose feet are on the wider side. While Naots tend to run shorter in the toe, these are long enough. I have to wear thin orthotics with them, and they fit. These shoes are dressy and very professional for meetings and office work. I would not dare walk a long way or stand for hours in them, though. I wish that like most other Naots, the toe box was a bit wider. But because they are made of fabric instead of leather, it isn't quite as bad. It is a lot of money to pay for fabric shoes. There is some engineering behind these, but to charge the same prices for fabric shoes as for leather shoes is absurd.These shoes look nicer on the foot than in the photo. They are good for pants or with a tailored suit and tights. They fit true to size for me, but they do not have quite as much arch support as I am used to in Naots. Naots are the only shoe I buy these days, so this was a bit disappointing for me, hence the 4 stars instead of 5.This is the second pair I ordered in this shoe and it's also too large. Don't know what to say other than it's a strange fitting shoe, it's also uncomfortable with little arch support, especially considering the brand and price. Disappointed because a navy pump with a block heel is so hard to find. I'll just keep looking.I love Naots in general, and I love this style: a dressier shoe I can walk in ALL DAY, and across miles (outstanding for business travel). You can see and feel the quality; these shoes are well made, and do what shoes are SUPPOSED to do: protect your feet, and make walking in them easier than walking barefoot. (As opposed to what we normally do with cute shoes - put up with a less comfortable walk!) The 40's are perfect for me, and since I wear an 8.5 in American sizing - normally a European 39 - I would suggest buying a size up if you're unfamiliar with Naots.I was worried that this product would be a little loose as it said 5/5.5, but it was not. It was extremely comfortable, but it wasn't long before I figured out that they needed a little additional padding where the toe area was located. They do exactly resemble the picture.I get a lot of compliments on these shoes and I always have to add that they are very comfortable! I'm in retail, but am in the back half of the store as administration. I normally don't stand on my feet at work a lot, but there have been times when I was asked to "shop for customers". This can go on for several hours in a day. Fortunately, I was wearing these shoes and was able to complete three hours of shopping for several customers without my feet killing me. LOVE THESE SHOES!I love Naot shoes. I can take them out of the box and wear them for an entire day and they always feel great. These were no exception. I usually wear a 38 but saw other reviews that said they ran small. The half size up worked for me but I have narrow feet. You may want to order a whole size up as they are narrow in the toe.