Among the obligatory things a husband must do is to financially provide for his wife. This is called nafaqah, and it is wajib upon the husband, irrespective of whether the wife has savings, an external income or work payments.
What the wife earns outside of nafaqah is hers and she has no obligation to provide for the household. If she wishes to contribute, then that is her choice and out of her own good will.
The nafaqah that the husband must provide for is the essential payments for a household and a family, based on their status. This would include accommodation, furnishing the house, food, bills, medical bills.
There is no specific percentage for how much nafaqah needs to amount to, as it would all be based on their individual circumstances.
Of course, the husband also has the responsibility of providing nafaqah to other dependents, like his children, grandchildren, parents, etc.
This is the shar'i ruling for nafaqah, but we know that for a marriage to be successful it's not just about money and demanding, because that will ruin a relationship. The husband and wife should aim at accommodating for each other to strengthen their household, religiously, morally and spiritually. They should try to be patient if they go through financial restraints, and work on overcoming it together as one family.
And Allah knows best.