If interest coverage ratio is      
greater than ≤ to Rating is Spread is
-100000 0.499999 D2/D 14.34%
0.5 0.799999 C2/C 10.76%
0.8 1.249999 Ca2/CC 8.80%
1.25 1.499999 Caa/CCC 7.78%
1.5 1.999999 B3/B- 4.62%
2 2.499999 B2/B 3.78%
2.5 2.999999 B1/B+ 3.15%
3 3.499999 Ba2/BB 2.15%
3.5 3.9999999 Ba1/BB+ 1.93%
4 4.499999 Baa2/BBB 1.59%
4.5 5.999999 A3/A- 1.29%
6 7.499999 A2/A 1.14%
7.5 9.499999 A1/A+ 1.03%
9.5 12.499999 Aa2/AA 0.82%
12.5 100000 Aaa/AAA 0.67%

[1]
Aswath Damodaran:
If yes, fill in the attached worksheet on operating leases
[2]
Aswath Damodaran:
If your most recent year's operating income is unusually low or high, you can use the average operating income from the last few years.
[3]
Aswath Damodaran:
Enter the interest expense from the most recent income statement.
[4]
Aswath Damodaran:
I use a 10 year government bond rate.