In Jiangsu Suqian, when the social security base is 11,400 yuan, the tax deduction calculation involves several aspects. Here's a breakdown:

1. Social Security Contributions:

• Pension Insurance: The individual contribution rate is usually 8%. So, for a base of 11,400 yuan, the monthly pension insurance contribution is ​
  ×8%=
  yuan.

• Medical Insurance: The individual contribution rate is around 2%, plus a possible fixed amount for major illness insurance. For simplicity, just considering the 2% for medical insurance, the contribution is ​
  ×2%=
  yuan.

• Unemployment Insurance: The individual contribution rate is generally 0.5%. So, the monthly unemployment insurance contribution is ​
  ×0.5%=
  yuan.

• Work-related Injury Insurance and Maternity Insurance: These are fully paid by the employer, so the individual doesn't have a direct contribution from this base amount.

2. Housing Provident Fund: The contribution rate for housing provident fund can range from 5% to 12% (decided by the employer within this range). If we assume a 10% contribution rate (for example), the monthly housing provident fund contribution is ​
   ×10%=
   yuan.

3. Personal Income Tax Calculation:

• First, calculate the taxable income. Taxable income = Wage income - Social security contributions - Housing provident fund - Tax exemption amount. In 2024, the monthly tax exemption amount is 5000 yuan.

• Let's assume no other deductions. The total deductions for social security and housing provident fund we calculated above are ​
  +++=
  yuan.

• Taxable income = ​
  −−=
  yuan.

• Looking at the individual income tax rate table, for a taxable income of 4063 yuan, the applicable tax rate is 3% and the quick - calculation deduction is 0. So, the personal income tax = ​
  ×3%=121.89
  yuan.

In conclusion, when the social security base in Suqian is 11,400 yuan, the total deductions including social security, housing provident fund, and personal income tax vary depending on specific contribution rates set by the employer for housing provident fund and other possible deductions. The above calculations are based on common rates and assumptions for reference only.