Weight Chart
Use this chart to estimate the adult weight of your Chihuahua. This is not a for sure thing, just a rough estimate. Also, the weight chart may not be very accurate up to 8 weeks do to milk fat. To convert ounces to pounds, divide ounces by 16.

Birth 0.16 lbs. 0.17 lbs. 0.19 lbs. 0.22  lbs. 0.25  lbs. 0.27 lbs. 0.28 lbs. 0.31 lbs. 0.34 lbs.
1 week 0.23 0.25 0.31 0.34 0.41 0.44 0.50 0.56 0.59
2 weeks 0.31 0.34 0.41 0.44 0.50 0.63 0.69 0.78 0.84
3 weeks 0.38 0.44 0.50 0.56 0.69 0.81 0.88 1.00 1.09
4 weeks 0.44 0.50 0.59 0.69 0.81 0.94 1.06 1.19 1.31
5 weeks 0.50 0.56 0.69 0.81 0.94 1.06 1.22 1.38 1.50
6 weeks 0.56 0.69 0.78 0.94 1.09 1.25 1.38 1.50 1.69
7 weeks 0.63 0.75 0.91 1.06 1.22 1.38 1.53 1.69 1.88
8 weeks 0.69 0.81 1.00 1.19 1.34 1.50 1.69 1.81 2.06
9 weeks 0.75 0.94 1.09 1.25 1.44 1.63 1.81 2.00 2.19
10 weeks 0.81 1.00 1.19 1.38 1.56 1.75 1.94 2.13 2.38
11 weeks 0.88 1.06 1.31 1.50 1.69 1.94 2.13 2.31 2.63
12 weeks 0.94 1.19 1.38 1.63 1.88 2.06 2.31 2.56 2.81
13 weeks 1.00 1.25 1.50 1.75 2.00 2.25 2.50 2.75 3.06
14 weeks 1.06 1.38 1.63 1.88 2.13 2.44 2.69 2.94 3.25
15 weeks 1.19 1.44 1.75 2.00 2.31 2.56 2.88 3.19 3.50
16 weeks 1.25 1.56 1.88 2.13 2.44 2.75 3.06 3.38 3.69
17 weeks 1.31 1.63 1.94 2.25 2.56 2.88 3.19 3.56 3.88
18 weeks 1.38 1.75 2.06 2.31 2.69 3.00 3.38 3.75 4.06
19 weeks 1.44 1.81 2.13 2.44 2.75 3.13 3.50 3.88 4.19
20 weeks 1.50 1.88 2.19 2.56 2.88 3.25 3.63 4.00 4.38
21 weeks 1.56 1.94 2.25 2.63 3.00 3.38 3.75 4.13 4.50
22 weeks 1.56 2.00 2.31 2.69 3.06 3.50 3.88 4.25 4.63
23 weeks 1.63 2.06 2.38 2.75 3.13 3.56 4.00 4.38 4.75
24 weeks 1.63 2.06 2.44 2.81 3.19 3.63 4.06 4.44 4.88
25 weeks 1.69 2.13 2.50 2.88 3.25 3.69 4.13 4.50 4.94
26 weeks 1.69 2.13 2.50 2.94 3.31 3.75 4.19 4.56 5.00
18 Months 2.00 lbs. 2.50 lbs. 3.00 lbs. 3.50 lbs. 4.00 lbs. 4.50 lbs. 5.00 lbs. 5.50 lbs. 6.00 lbs.