TLDR; For the waist, buy 4" larger than your normal pant size. (For example, if you wear a 30 in Levis, buy a 34 in these overalls). For the inseam, order a size longer than your normal inseam (if possible) to account for shrinkage. Onto the longer review... These overalls are great, the price is fantastic, and the quality and construction feels like something timeless and straight out of the 1930s. I do question their claim that they are unchanged since 1912, considering that they have two zippers (and zippers didn't really start gaining widespread adoption until a few decades later), but I digress...onto the fit! First of all, these are a rigid, unwashed denim. They will shrink upwards of 3% when washed and dried. As with most garments, shrinkage in the width will usually stretch back out with wear. Shrinkage in the length will not. Therefore, I recommend buying an inseam that is longer than you normally wear (if possible). Shrinkage can be unpredictable, so you might end up with overalls that are too long, but it's easy to get them hemmed or wear them cuffed. That's the easy part. Onto the waist measurement... Vintage clothing used to run true-to-size. If something said it was a 30 waist, it would actually measure 30" in the waist. Over the past few decades, most brands have adopted "vanity sizing". A size 30 in Men's Levis (and most brands) will usually measure 32". A few brands still run true-to-size (like the classic Dickies 874, which is why you usually buy 2 sizes larger in Dickies than you wear in other garments). These overalls, from what I can tell, actually run true-to-size. A size 30 in these overalls will actually measure 30" around the waist. But these aren't pants, and shouldn't fit you tight around the waist like normal pants. you need a little wiggle room for them to be comfortable and hang properly. So you'll want to add an additional 2" to your true waist measurement. In other words: -If you wear a size 30 in Levi's 501 and similar pants that use vanity sizing, then you'll probably want a size 34 in these overalls. -If you wear a size 32 in Dickies 874 and similar pants that run true-to-size, then you'll probably want a size 34 in these overalls. -Alternatively, measure your true waist (around your belly button) with a tailor's measuring tape, add 2" to that, and that is likely the size you'll want to buy. I don't know why companies make it so difficult to determine fit of their garments. Customers are left with a generic size chart that doesn't do anything. As a customer, we need to know the exact measurements of the garment. We need to know how it compares to other brands we're used to. It's also useful to know what size the model is wearing in the photos. Instead, we don't get any of that. We must order multiple sizes online and then return the ones that don't fit. Very wasteful. So hopefully this review helps someone out.