If your social security base in Hangzhou, Zhejiang is 11,700 yuan, the total social security contribution is 2,400.45 yuan, with the unit paying 1,656.75 yuan and the individual paying 743.7 yuan. The calculation details are as follows:

1. Endowment Insurance: The unit contribution rate is 16%, so the unit pays ​
   ×16%=
   yuan; the individual contribution rate is 8%, so the individual pays ​
   ×8%=
   yuan.

2. Medical Insurance: The unit contribution rate is 9.5%, so the unit pays ​
   ×9.5%=1111.5
   yuan; the individual contribution rate is 2%, so the individual pays ​
   ×2%=
   yuan.

3. Unemployment Insurance: The unit contribution rate is 0.5%, so the unit pays ​
   ×0.5%=58.5
   yuan; the individual contribution rate is 0.5%, so the individual pays ​
   ×0.5%=58.5
   yuan.

4. Work-related Injury Insurance: The unit contribution rate is 0.275% (the rate may vary by industry), so the unit pays ​
   ×0.275%=32.175
   yuan, and individuals do not pay.

5. Maternity Insurance: Has been merged into medical insurance, and individuals do not pay.

In summary, when the social security base in Hangzhou is 11,700 yuan, the unit pays a total of 1872 + 1111.5 + 58.5 + 32.175 = 3074.175 yuan, and the individual pays a total of 936 + 234 + 58.5 = 1228.5 yuan. However, it should be noted that the actual situation may be adjusted according to local policies. It is recommended to consult the local social security department for the most accurate information.

above is based on general policies and rates. If you want to know about any special policies in Hangzhou or how to adjust your contributions based on your personal situation, I'd be happy to further assist you.