Harper Wilde to Marks & Spencer bra size

The short answer

Harper Wilde 34D is Marks & Spencer 34D by the two brands' own charts.

Cups are counted along each brand's own letter order, and the band is carried across unchanged.

Every Harper Wilde size read across to Marks & Spencer. US sizes on the left, UK on the right.
Harper Wilde	Marks & Spencer, by chart	Same label	Marks & Spencer also prints
34A	34A	not published	not published
34B	34B	not published	not published
34C	34C	not published	not published
34D	34D	not published	not published
34DD	34DD	not published	not published
34DDD	34E	not published	not published

Neither chart publishes the body each size is built for, so the rows line up the labels. Tinted rows change label or sit between two sizes. Read from the two charts only; no formula and no averaging.

What wearers say

Charts describe a garment. People who own both brands describe a fit, and their answer ranks above this table once five of them stand behind it. Pick your size in the converter to see whether there are enough yet.

Open in the converter Add an item you own

Sources

Harper Wilde size guide, read on 2026-09-18. Harper Wilde on TrueToSize
Marks & Spencer size guide, read on 2026-09-18.

Marks & Spencer to Harper Wilde