In most cases, the interest paid on mortgage loans is deductible from your federal income taxes. You may therefore want to make financing decisions on an after-tax basis, particularly when you are comparing a tax deductible mortgage loan to a consumer loan. To do so, you need to know your marginal tax rate. This is the amount of each additional dollar of income that is taxed away. It is also the amount of each dollar of tax-deductible expenses that reduces your taxes. So, if you know your marginal tax rate, you can easily determine how much tax you will save. More->