Mortgage rate movements are a bit unsteady today. For example, according to Zillow, the average 30-year fixed rate has decreased by one basis point to 6.72%, while the 15-year fixed rate is up three basis points to 6.12%. The 20-year fixed interest rate has decreased by three basis points to 6.55%.This could be the trend for a while — occasional ups and downs with few drastic changes. Mortgage rates aren’t expected to plummet anytime soon, so if you’re otherwise ready to buy a house, consider shopping for homes now. Remember, you can always refinance your loan in a few years if rates fall more significantly.Dig deeper: Should you buy a house? How to know if you’re ready.Here are the current mortgage rates, according to the latest Zillow data: 30-year fixed: 6.72% 20-year fixed: 6.55% 15-year fixed: 6.12% 5/1 ARM: 6.73% 7/1 ARM: 6.54% 30-year VA: 6.15% 15-year VA: 5.66% 5/1 VA: 6.38% Remember, these are the national averages and rounded to the nearest hundredth.Learn more: 5 strategies for getting the lowest mortgage ratesThese are today’s mortgage refinance rates, according to the latest Zillow data: 30-year fixed: 6.70% 20-year fixed: 6.53% 15-year fixed: 5.99% 5/1 ARM: 6.05% 7/1 ARM: 6.70% 30-year VA: 6.04% 15-year VA: 5.83% 5/1 VA: 5.84% Again, the numbers provided are national averages rounded to the nearest hundredth. Mortgage refinance rates are often higher than rates when you buy a house, although that’s not always the case. Use Yahoo Finance’s free mortgage calculator to see how various interest rates and term lengths will impact your monthly mortgage payment. It also shows how the home price and down payment amount play into things.Our calculator includes homeowners insurance and property taxes in your monthly payment estimate. You even have the option to enter costs for private mortgage insurance (PMI) and homeowners’ association dues if those apply to you. These details result in a more accurate monthly payment estimate than if you simply calculated your mortgage principal and interest.There are two main advantages to a 30-year fixed mortgage: Your payments are lower, and your monthly payments are predictable.A 30-year fixed-rate mortgage has relatively low monthly payments because you’re spreading your repayment out over a longer period of time than with, say, a 15-year mortgage. Your payments are predictable because, unlike with an adjustable-rate mortgage (ARM), your rate isn’t going to change from year to year. Most years, the only things that might affect your monthly payment are any changes to your homeowners insurance or property taxes.The main disadvantage to 30-year fixed mortgage rates is mortgage interest — both in the short and long term.A 30-year fixed term comes with a higher rate than a shorter fixed term, and it’s higher than the intro rate to a 30-year ARM. The higher your rate, the higher your monthly payment. You’ll also pay much more in interest over the life of your loan due to both the