If they have enough suction to seal to your face for 3 to 4 seconds, they're a good fit. If they pop off, look for a smaller size.
[header] How to fit swimming goggles [title] Test the seals of the eye pieces with your face shape. [step] Place each pair of goggles over your eyes without fitting the straps around your head. Use your fingers to press the goggles gently onto your eyes.