Table 2.

Mean cycle lengths, bleed lengths, per-user cycle length variations, follicular phase lengths and luteal phase lengths in cohorts of cycles by user age

Age range in years	Users (% of total)	Cycles (% of total)	Mean ± std cycle length in days	Mean ± std bleed length in days	Mean ± std per-user cycle length variation in days	Mean ± std follicular phase length in days	Mean ± std luteal phase length in days
18–24	13,391 (11%)	50,789 (8%)	30.3 ± 5.7	4.2 ± 1.4	2.9 ± 2.7	18.0 ± 5.7	12.2 ± 2.5
25–29	43,297 (35%)	209,968 (34%)	29.9 ± 5.5	4.0 ± 1.4	2.8 ± 2.7	17.6 ± 5.6	12.3 ± 2.4
30–34	41,571 (33%)	207,156 (34%)	29.2 ± 5.1	3.9 ± 1.5	2.6 ± 2.4	16.8 ± 5.2	12.4 ± 2.3
35–39	19,410 (16%)	102,553 (17%)	28.2 ± 4.4	3.8 ± 1.5	2.3 ± 2.1	15.7 ± 4.5	12.5 ± 2.4
40–45	6,948 (6%)	42,044 (7%)	27.4 ± 4.3	3.7 ± 1.5	2.4 ± 2.4	14.8 ± 4.3	12.5 ± 2.4
All cycles	124,646	612,613	29.3 ± 5.2	4.0 ± 1.5	2.6 ± 2.5	16.9 ± 5.3	12.4 ± 2.4