Dog age chart: dog years to human years by size

By the Bowl Figures editorial team · Reviewed Nov 8, 2026 · Sources

The human age of a dog of 1 to 16 years in each of four sizes, worked out by the same engine as the dog age calculator, with the DNA clock and the seven-year rule beside them.

Dog age (years)	Small (20 lb or less)	Medium (21 to 50 lb)	Large (51 to 100 lb)	Giant (over 100 lb)	DNA clock (Wang et al.)	7× rule
1	15	15	15	15	31.0	7
2	24	24	24	24	42.1	14
3	28	28	29.5	31.5	48.6	21
4	32	32	35	39	53.2	28
5	36	36	40.5	46.5	56.8	35
6	40	42	46	54	59.7	42
7	44	47	51.5	61.5	62.1	49
8	48	51	57	69	64.3	56
9	52	56	62.5	76.5	66.2	63
10	56	60	68	84	67.8	70
11	60	65	73.5	91.5	69.4	77
12	64	69	79	99	70.8	84
13	68	74	84.5	106.5	72.0	91
14	72	78	90	114	73.2	98
15	76	83	95.5	121.5	74.3	105
16	80	87	101	129	75.4	112

Every size is 15 at 1 and 24 at 2, the figures AVMA’s chart and Merck’s table share. The medium column is AVMA’s chart itself. After 2, the small column adds 4 human years a year (Merck’s table and PetMD), the large 5.5 and the giant 7.5, the middle of PetMD’s 5 to 6 and 7 to 8.

The DNA clock is 16 × ln(dog age) + 31, fitted by Wang et al. on 104 Labrador retrievers: it makes a young dog much older than the charts and an old dog younger. The seven-year rule is in no veterinary source used here.

AAHA’s 2019 guidelines do not convert ages: they place a dog in a life stage. Every figure is an estimate; your veterinarian can tell you where your own dog is.

Each age, worked out

Calculators

Dog age calculator