Exhibit 12

SIMON PROPERTY GROUP, L.P.
Computation of Ratio of Earnings to Fixed Charges and Preferred Stock Dividends
(in thousands)

|                                                                 |                                                                   | For the Year Ended December 31,                                           |          
|---------------------------------------------------------------- | ----------------------------------------------------------------- | ------------------------------------------------------------------------- | ---------
|
|Earnings:                                                        |                                                                   |                                                                           |          
|                                                                 | Pre-tax income from continuing operations                         |                                                                           | $        
|                                                                 | Add:                                                              |                                                                           |          
|                                                                 |                                                                   | Pre-tax income from 50% or greater than 50% owned unconsolidated entities |          
|                                                                 |                                                                   | Minority interest in income of majority owned subsidiaries                |          
|                                                                 |                                                                   | Distributed income from less than 50% owned unconsolidated entities       |          
|                                                                 |                                                                   | Amortization of capitalized interest                                      |          
|Fixed Charges                                                    |                                                                   |                                                                           | 958,818  
|Less:                                                            |                                                                   |                                                                           |          
|                                                                 |                                                                   | Income from unconsolidated entities                                       |          
|                                                                 |                                                                   | Interest capitalization                                                   |          
|                                                                 |                                                                   |                                                                           |          
|Earnings                                                         |                                                                   | $                                                                         | 1,659,243
|                                                                 |                                                                   |                                                                           |          
|Fixed Charges:                                                   |                                                                   |                                                                           |          
|                                                                 | Portion of rents representative of the interest factor            |                                                                           |          
|                                                                 | Interest on indebtedness (including amortization of debt expense) |                                                                           |          
|                                                                 | Interest capitalized                                              |                                                                           |          
|                                                                 |                                                                   |                                                                           |          
|Fixed Charges                                                    |                                                                   | $                                                                         | 958,818  
|                                                                 |                                                                   |                                                                           |          
|Ratio of Earnings to Fixed Charges and Preferred Stock Dividends |                                                                   |                                                                           | 1.73x    
|                                                                 |                                                                   |                                                                           |          

For
purposes of calculating the ratio of earnings to fixed charges, "earnings" have been computed by adding fixed charges, excluding capitalized interest, to pre-tax income
from continuing operations including income from minority interests and our share of pre-tax income from 50%, or greater than 50%, owned unconsolidated entities which have fixed charges,
and including distributed operating income from less than 50% owned unconsolidated joint ventures instead of income from the less than 50% owned unconsolidated joint ventures. There are generally no
restrictions on our ability to receive distributions from our joint ventures where no preference in favor of the other owners of the joint venture exists. "Fixed charges" consist of interest costs,
whether expensed or capitalized, the interest component of rental expenses, preferred distributions, and amortization of debt issue costs.

118

---



QuickLinks