As a supplement to the main motor vehicle rate chart, the OCCC also provides this chart expressing the $12.50 and $15 add-on rates as effective interest rates for contract terms ranging from 1 to 84 months.
| Term in # of months | $12.50 per $100.00 per year | $15 per $100.00 per year |
|---|---|---|
| 1 | 18 | 18 |
| 2 | 18 | 19.9452 |
| 3 | 18.6541 | 22.3624 |
| 4 | 19.8374 | 23.767 |
| 5 | 20.5996 | 24.6655 |
| 6 | 21.1215 | 25.2754 |
| 7 | 21.4935 | 25.7054 |
| 8 | 21.7659 | 26.016 |
| 9 | 21.9688 | 26.2435 |
| 10 | 22.1215 | 26.4109 |
| 11 | 22.2367 | 26.5338 |
| 12 | 22.3232 | 26.6226 |
| 13 | 22.3875 | 26.6849 |
| 14 | 22.434 | 26.7265 |
| 15 | 22.4664 | 26.7513 |
| 16 | 22.4872 | 26.7626 |
| 17 | 22.4985 | 26.7628 |
| 18 | 22.502 | 26.754 |
| 19 | 22.4988 | 26.7375 |
| 20 | 22.4901 | 26.7148 |
| 21 | 22.4768 | 26.6867 |
| 22 | 22.4594 | 26.6542 |
| 23 | 22.4387 | 26.6178 |
| 24 | 22.415 | 26.5783 |
| 25 | 22.3889 | 26.536 |
| 26 | 22.3605 | 26.4915 |
| 27 | 22.3304 | 26.4449 |
| 28 | 22.2986 | 26.3968 |
| 29 | 22.2654 | 26.3472 |
| 30 | 22.2311 | 26.2964 |
| 31 | 22.1957 | 26.2446 |
| 32 | 22.1594 | 26.192 |
| 33 | 22.1224 | 26.1387 |
| 34 | 22.0847 | 26.0848 |
| 35 | 22.0464 | 26.0305 |
| 36 | 22.0077 | 25.9759 |
| 37 | 21.9686 | 25.921 |
| 38 | 21.9292 | 25.8659 |
| 39 | 21.8895 | 25.8106 |
| 40 | 21.8496 | 25.7553 |
| 41 | 21.8095 | 25.7 |
| 42 | 21.7693 | 25.6447 |
| 43 | 21.729 | 25.5894 |
| 44 | 21.6886 | 25.5343 |
| 45 | 21.6483 | 25.4793 |
| 46 | 21.6079 | 25.4245 |
| 47 | 21.5679 | 25.3699 |
| 48 | 21.5273 | 25.3155 |
| 49 | 21.4871 | 25.2613 |
| 50 | 21.4469 | 25.2074 |
| 51 | 21.4069 | 25.1537 |
| 52 | 21.367 | 25.1003 |
| 53 | 21.3272 | 25.0473 |
| 54 | 21.2876 | 24.9945 |
| 55 | 21.2481 | 24.942 |
| 56 | 21.2088 | 24.8898 |
| 57 | 21.1696 | 24.838 |
| 58 | 21.1307 | 24.7865 |
| 59 | 21.0919 | 24.7354 |
| 60 | 21.0533 | 24.6845 |
| 61 | 21.0149 | 24.6341 |
| 62 | 20.9767 | 24.5839 |
| 63 | 20.9387 | 24.5342 |
| 64 | 20.9009 | 24.4847 |
| 65 | 20.8633 | 24.4357 |
| 66 | 20.8259 | 24.387 |
| 67 | 20.7888 | 24.3386 |
| 68 | 20.7518 | 24.2906 |
| 69 | 20.7151 | 24.243 |
| 70 | 20.6786 | 24.1957 |
| 71 | 20.6423 | 24.1488 |
| 72 | 20.6063 | 24.1022 |
| 73 | 20.5705 | 24.0559 |
| 74 | 20.5349 | 24.0101 |
| 75 | 20.4995 | 23.9645 |
| 76 | 20.4643 | 23.9194 |
| 77 | 20.4294 | 23.8745 |
| 78 | 20.3947 | 23.83 |
| 79 | 20.3602 | 23.7859 |
| 80 | 20.3259 | 23.7421 |
| 81 | 20.2919 | 23.6986 |
| 82 | 20.2581 | 23.6555 |
| 83 | 20.2245 | 23.6127 |
| 84 | 20.1911 | 23.5702 |