A button gap is not always solved by choosing a larger shirt dress. Extra size may help when the whole upper body is too close, but the problem can also involve button placement, the shape of the bust, or fabric that pulls when you sit. Find the cause before adding more volume everywhere.
Fasten the dress and stand neutrally. Look for tension lines running toward a button and check whether the placket lies flat between fasteners. If the gap is already visible before you move, it is unlikely to become less noticeable during an ordinary day.
Separate the fit zones
Raise your arms gently and then bring them forward. A tight upper back can pull the front open even when the chest measurement seems adequate. A sleeve that restricts movement may have the same effect. Compare shoulder, armhole, and back fit rather than judging the front in isolation.
Now sit. The waist and hip sections take on a different shape, especially if you have tied a belt. Loosen the belt and see whether the gap changes. A belt can be a styling choice, but it should not be required to force the dress into a position that makes the front strain.
Button spacing also matters near the neckline and lower skirt. You may want one opening height for coverage and discover that the available buttons offer either too much or too little. At the bottom, confirm that the unfastened section allows a normal stride without opening farther than you prefer.
Consider alterations before making them
An extra concealed snap may help a small local opening in an otherwise suitable garment, but it is not a cure for inadequate room. It can create a new pulling point or show through thin fabric. Ask a tailor to assess it before committing, and do not add hardware while deciding whether to return the dress.
A different button layout, a sewn-front design, or a roomier cut may be a cleaner solution. Check the back of the dress too: a larger size that solves the placket but leaves excessive fabric at the shoulders may not be the best trade.
Choose the dress you can wear while sitting and reaching normally. Keeping a front closed should not require holding a fixed pose or repeatedly checking it throughout the day.
