The concept of 'runoff'

Milarky

This is scarcely a unique idea, but one way to view your 'stoozpot' is the value it has assuming that all amounts are repaid when the 0% (or other low rate) reverts and it is no longer profitable. Just taking the size of your pot as the sum of the outstanding balances is uninformative whereas the 'runoff' value puts the correct value on each sum - half for a six months, or three quarters for a nine months deal, and so on - so that you can then 'add up' your cards.

Here is an example:

Card A: Balance owing £5000 with 5 months remaining.... [x5/12] = £2083
Card B: Balance owing £3500 with 8 months remaining.... [x8/12] = £2333
Card C: Balance owing £1500 with 4 months remaining.... [x4/12] = £500

Thus although the stooz-pot is a nice round 10k it is worth less than this sat in your bank. It is only worth just under half this - at £4916. In other words you are sitting on a year's free interest from a balance of just under £5k (which will get you about £176 net) which must be repaid in an average time of about 6 months

This approach can be refined. For instance minimum payments will eat into each balance slightly in most cases and the effect on the value of each of the above (assuming 2% per month) differs according to how long (how many payments) this takes place over:

Card A: Balance owing £5000 with 5 months remaining.... [x5/12] = £2083
4 min payments (2% reducing) £388.16 repaid.......................... = - £82
Card B: Balance owing £3500 with 8 months remaining.... [x8/12] = £2333
7 min payments (2% reducing) £461.56 repaid.......................... = -£157
Card C: Balance owing £1500 with 4 months remaining.... [x4/12] = £ 500
3 min payments (2% reducing) £88.21 repaid........................... = -£ 15

So the new 'runoff' value of this stoozpot of '£10k' is £4662