The Chihuahua Weight Chart is presented as a guide to estimate a mature weight within a quarter of a pound or so. Weight estimates before the age of 8 weeks old are difficult to predict and are usually inaccurate because the puppy may still be nursing or in the weaning stage and may be heavier due to fat content from the mother's rich milk.
While this chart has proven through the years to be a good guide please be aware that many things can affect the mature weight of a puppy. Factors that can affect the mature weight include the breeder's own bloodline, genetics, diet, activity level and the individual health of the puppy.
The left-hand column of the table gives the age of the puppy in weeks. To determine the puppy's expected weight when fully grown, weigh the puppy in ounces (use a good quality scale such as a postal scale); compare the line of figures (ounces) against the number of weeks of age, and take the figure nearest to the present weight of the puppy. The expected adult weight of the puppy will be given at the foot of the column in which the figure nearest to its weight occurs.
NOTE: Weights before the age of eight weeks are liable to vary.
| Birth | 2½ oz. | 2¾ oz. | 3 oz. | 3½ oz. | 4 oz. | 4¼ oz. | 4½ oz. | 5 oz. | 5½ oz. |
| 1 week | 3¾ | 4 | 5 | 5½ | 6½ | 7 | 8 | 9 | 9½ |
| 2 weeks | 5 | 5½ | 6½ | 7 | 9 | 10 | 11 | 12½ | 13½ |
| 3 weeks | 6 | 7 | 8 | 9 | 11 | 13 | 14 | 16 | 17½ |
| 4 weeks | 7 | 8 | 9½ | 11 | 13 | 15 | 17 | 19½ | 21 |
| 5 weeks | 8 | 9 | 11 | 13 | 15 | 17 | 19½ | 22 | 24 |
| 6 weeks | 9 | 11 | 12½ | 15 | 17½ | 20 | 22 | 24 | 27 |
| 7 weeks | 10 | 12 | 14½ | 17 | 19½ | 22 | 24½ | 27 | 30 |
| 8 weeks | 11 | 13 | 16 | 19 | 21½ | 24 | 27 | 29 | 33 |
| 9 weeks | 12 | 15 | 17½ | 20 | 23 | 26 | 29 | 32 | 35 |
| 10 weeks | 13 | 16 | 19 | 22 | 25 | 28 | 31 | 34 | 38 |
| 11 weeks | 14 | 17 | 21 | 24 | 27 | 31 | 34 | 37 | 42 |
| 12 weeks | 15 | 19 | 22 | 26 | 30 | 33 | 37 | 41 | 45 |
| 13 weeks | 16 | 20 | 24 | 28 | 32 | 36 | 40 | 44 | 49 |
| 14 weeks | 17 | 22 | 26 | 30 | 34 | 39 | 43 | 47 | 52 |
| 15 weeks | 19 | 23 | 28 | 32 | 37 | 41 | 46 | 51 | 56 |
| 16 weeks | 20 | 25 | 30 | 34 | 39 | 44 | 49 | 54 | 59 |
| 17 weeks | 21 | 26 | 31 | 36 | 41 | 46 | 51 | 57 | 62 |
| 18 weeks | 22 | 28 | 33 | 37 | 43 | 48 | 54 | 60 | 65 |
| 19 weeks | 23 | 29 | 34 | 39 | 44 | 50 | 56 | 62 | 67 |
| 20 weeks | 24 | 30 | 35 | 41 | 46 | 52 | 58 | 64 | 70 |
| 21 weeks | 25 | 31 | 36 | 42 | 48 | 54 | 60 | 66 | 72 |
| 22 weeks | 25 | 32 | 37 | 43 | 49 | 56 | 62 | 68 | 74 |
| 23 weeks | 26 | 33 | 38 | 44 | 50 | 57 | 64 | 70 | 76 |
| 24 weeks | 26 | 33 | 39 | 45 | 51 | 58 | 65 | 71 | 78 |
| 25 weeks | 27 | 34 | 40 | 46 | 52 | 59 | 66 | 72 | 79 |
| 26 weeks | 27 | 34 | 40 | 47 | 53 | 60 | 67 | 73 | 80 |
| 18 months (full grown) | 2 lb. | 2½ lb. | 3 lb. | 3½ lb. | 4 lb. | 4½ lb. | 5 lb. | 5 ½ lb. | 6 |
The Chihuahua Weight Chart was extracted from a book titled "The Complete Chihuahua Encyclopedia" by Hilary Harmar, which was published in 1972 by the Arco Publishing Company, Inc., New York, NY.