Mortgage rates are down across the board today. According to Zillow, the 30-year fixed mortgage rate has decreased by nine basis points to 6.54%, and the 15-year fixed rate has dropped by 11 basis points to 5.82%.Now could be a good time to buy a house. Interest rates have gone down, and they could increase later as Trump’s tariffs on Mexico, Canada, and China develop. You would also beat the bustle of the spring home-buying season, and while this likely means fewer houses on the market, it also usually means less competition.Read more: Should you lock in a mortgage rate — and if so, when?Here are the current mortgage rates, according to the latest Zillow data: 30-year fixed: 6.54% 20-year fixed: 6.32% 15-year fixed: 5.82% 5/1 ARM: 6.64% 7/1 ARM: 6.89% 30-year VA: 6.02% 15-year VA: 5.40% 5/1 VA: 6.54% Remember, these are the national averages and rounded to the nearest hundredth.Learn more: 5 strategies to get the lowest mortgage ratesHave questions about buying, owning, or selling a house? Submit your question to Yahoo’s panel of Realtors using this Google form. Here are today’s mortgage refinance interest rates, according to the latest Zillow data: 30-year fixed: 6.55% 20-year fixed: 6.24% 15-year fixed: 5.81% 5/1 ARM: 6.77% 7/1 ARM: 6.32% 30-year VA: 5.94% 15-year VA: 5.51% 5/1 VA: 6.11% 30-year FHA: 6.41% 15-year FHA: 5.81% As with the purchase mortgage rates, these are national averages we’ve rounded to the nearest hundredth. Refinance rates can be higher than purchase mortgage rates, but that isn’t always the case. Yahoo Finance has a free mortgage payment calculator to help you see how various mortgage rates will impact your monthly payments.Our calculator goes even deeper by including factors like homeowners insurance and property taxes in your calculation. You can even add private mortgage insurance costs and HOA dues if they apply to you. These monthly expenses, along with your mortgage principal and interest rate, will give you a realistic idea of what your monthly payment could be.A mortgage interest rate is a fee for borrowing money from your lender, expressed as a percentage. There are two basic types of mortgage rates: fixed and adjustable rates.A fixed-rate mortgage locks in your rate for the entire life of your loan. For example, if you get a 30-year mortgage with a 6% interest rate, your rate will stay at 6% for the entire 30 years. (Unless you refinance or sell the home.)An adjustable-rate mortgage keeps your rate the same for the first few years, then changes it periodically. Let’s say you get a 5/1 ARM with an introductory rate of 6%. Your rate would be 6% for the first five years and then the rate would increase or decrease once per year for the last 25 years of your term. Whether your rate goes up or down depends on several factors, such as the economy and U.S. housing market.At the beginning of your mortgage term, most of your monthly payment goes toward interest. As time passes, less of your payment