Start helmet sizing with your head circumference and the size chart for the particular model. A measurement alone is not enough: equally sized models from the same manufacturer can feel different. Try the exact model before buying.
Head shape matters too. A helmet’s interior may suit a rounder or a longer head. Localised forehead pressure can therefore point to a shape mismatch, and a larger size is not always the answer. Compare several models with a knowledgeable retailer.
Some helmets allow finer adjustment through model-specific head liners and cheek pads. Professional fitting starts by assessing head shape, then uses a try-on and checks the adjustments. This helps identify a suitable combination instead of relying solely on the size letter.
Allow time to compare helmets in the shop and explain where pressure feels uneven. Ask about padding options before buying; have a specialist make adjustments in accordance with the particular model’s instructions.