Helpful response by SouthJ as always.
FICO used to ignore any revolving account if the credit limit was huge enough. A number of people thought the threshold for old models was 35k (thus 34.9k or less would be completely safe) and that it might be higher for FICO 8. The last round of testing seemed to show that 50k was safe for FICO 8.
Bear in mind that several credit monitoring services will erroneously round util % to the nearest integer (in their front-end summary page) rather than the way the FICO algorithm actually works, which is to round UP. Thus Credit Check Total, Credit Karma, and I think even myFICO Ultimate have been known to round 0.3% to 0% and 9.2% to 9%. The true FICO algorithm (on the back end) rounds those to 1% and 10% respectively.
That's important to know because 0% and 10% both involve scoring penalties.
