If you are talking about an Agency Jumbo - those loans above $417k and below $625k ($625,000 is the max for most high-cost counties such as Alameda and Contra Costa - the limit varies per county), they will usually accept a maximum of 45% for sure - some may go to 50%. These are Fannie Mae or Freddie Mac loans. If Mortgage Insurance is involved, their ratios take priority and they will limit it to 41% or less.
The DTI then is your full payment (Principal, Interest, Taxes, Insurance + any HOA fee) along with any monthly debt (your installment debt such as a car payment and the minimum monthly charge showing up on your credit bureau for any credit card payments), divided by your gross income.
Income calculations will vary dependent on full/part-time work, commission or seasonal work, retirement or social security income.
Any loan above the Fannie/Freddie limit for that county is considered a true Jumbo loan and they vary in what they will accept. Some will go to 45%, others limit it to 41% or less.