How do you measure armhole - up or down or around curve of armhole?

To measure the armhole, you should measure around the curve of the armhole. Start at the shoulder seam and follow the curve down to the underarm seam, ensuring the tape measure lays flat against the body. This measurement provides a more accurate fit for garments, allowing for proper movement and comfort. It’s essential to keep the tape measure snug but not tight during the measurement.