Standardize size of buttons

Hi,
Is there a way to make all the buttons the same size regardless of the text inside the buttons? We picked the large size button, but the size of it changes to the text we write rather than changing the font-size to the box. We tried to change the font size for some of the smaller words which worked, but it’s hard to get the boxes the same size. We also tried to get around it by putting in fake text, the same color as the button, but when you re-size the browser it will show up. Across Chrome, it looks fine, but it looks different on Firefox and IE.

Is there any way to standardize the size of the buttons disregarding the amount of text?

Thanks!