# Can you calculate mortgage amortization tabes? **URL:** \ **Category:** Factual Questions\ **Created:** [February 8, 2005, 3:46am UTC](https://boards.straightdope.com/t/can-you-calculate-mortgage-amortization-tabes/288942 "2005-02-08T03:46:28Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![PosterChild](https://avatars.discourse-cdn.com/v4/letter/p/e274bd/32.png) [@PosterChild](https://boards.straightdope.com/u/PosterChild)\ **Post date:** [February 8, 2005, 3:46am UTC](https://boards.straightdope.com/t/can-you-calculate-mortgage-amortization-tabes/288942/1 "2005-02-08T03:46:28Z")
So I’m (hopefully) buying a house and I’m confused by the amortization tables. Is there a simple equation to calculate what the monthly payment would be for a 30yr fixed loan? As opposed to having to look it up for every case in a table. I want to make an excel sheet that will calculate payments depending on amount of loan, interest rate, and points, but I don’t know how they calculate the required amount of principle that’s paid on the first months payment. Is there a straightforward calculation? PC ---
**Author:** ![wolf\_meister](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolf_meister/32/15202_2.png) [@wolf\_meister](https://boards.straightdope.com/u/wolf_meister)\ **Post date:** [February 8, 2005, 3:54am UTC](https://boards.straightdope.com/t/can-you-calculate-mortgage-amortization-tabes/288942/2 "2005-02-08T03:54:07Z")
It is rather complex. Actually I wrote 2 calculators for my website that will do it for you: [www.1728.com/mortpmts.htm](http://www.1728.com/mortpmts.htm) and [www.1728.com/mortmnts.htm](http://www.1728.com/mortmnts.htm) The first one gives a yearly summary and the second gives a month by month detail. Hey. it’s free. ---
**Author:** ![wolf\_meister](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolf_meister/32/15202_2.png) [@wolf\_meister](https://boards.straightdope.com/u/wolf_meister)\ **Post date:** [February 8, 2005, 3:56am UTC](https://boards.straightdope.com/t/can-you-calculate-mortgage-amortization-tabes/288942/3 "2005-02-08T03:56:43Z")
Okay, if you just want to know the monthly payment then go here: [www.1728.com/calcloan.htm](http://www.1728.com/calcloan.htm) Want to see the formula with a worked out example? Go here: [http://www.1728.com/loanform.htm](http://www.1728.com/loanform.htm) ---
**Author:** ![CurtC](https://avatars.discourse-cdn.com/v4/letter/c/ce73a5/32.png) [@CurtC](https://boards.straightdope.com/u/CurtC)\ **Post date:** [February 8, 2005, 3:57am UTC](https://boards.straightdope.com/t/can-you-calculate-mortgage-amortization-tabes/288942/4 "2005-02-08T03:57:40Z")
Excel has those formulas built-in. They’re FV, PV, IPMT, NPER, and PMT. I’m not sure what you’re asking with the “required amount of principle that’s paid on the first month’s payment.” ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [February 8, 2005, 4:02am UTC](https://boards.straightdope.com/t/can-you-calculate-mortgage-amortization-tabes/288942/5 "2005-02-08T04:02:09Z")
There are dozens of free sites online that will easily and quickly calculate a mortgage payment. [Here’s one site](http://mortgages.interest.com/content/calculators/index.asp) Some lender ads pop up along with the calculation and amort table but nothing too obnoxious. If you want to do it the hard way [How to calculate amortization tables by hand](http://www.hughchou.org/calc/formula.html) ---
**Author:** ![Civil\_Guy](https://avatars.discourse-cdn.com/v4/letter/c/d78d45/32.png) [@Civil\_Guy](https://boards.straightdope.com/u/Civil_Guy)\ **Post date:** [February 8, 2005, 4:02am UTC](https://boards.straightdope.com/t/can-you-calculate-mortgage-amortization-tabes/288942/6 "2005-02-08T04:02:41Z")
Probably best to use someone else’s calculator - IMHO, the terminology used by financial types tends to get pretty obscure. Still, if you have too much time on your hands, I _think_ the correct Excel formula is: PV(rate,nper,pmt,fv,type) Check the Excel docs for more details. Warning - if you’re using monthly periods, the interest _per period_ is AnnualRate / 12. Otherwise, you get really strange results. Which is to say - use someone else’s calculator. ---
**Author:** ![Civil\_Guy](https://avatars.discourse-cdn.com/v4/letter/c/d78d45/32.png) [@Civil\_Guy](https://boards.straightdope.com/u/Civil_Guy)\ **Post date:** [February 8, 2005, 4:07am UTC](https://boards.straightdope.com/t/can-you-calculate-mortgage-amortization-tabes/288942/7 "2005-02-08T04:07:07Z")
> [@CurtC](#): > > Excel has those formulas built-in. They’re FV, PV, IPMT, NPER, and PMT. > > I’m not sure what you’re asking with the “required amount of principle that’s paid on the first month’s payment.” Is **PosterChild** maybe trying to figure out the down payment to achieve a given monthly payment? ---
**Author:** ![PosterChild](https://avatars.discourse-cdn.com/v4/letter/p/e274bd/32.png) [@PosterChild](https://boards.straightdope.com/u/PosterChild)\ **Post date:** [February 8, 2005, 6:52am UTC](https://boards.straightdope.com/t/can-you-calculate-mortgage-amortization-tabes/288942/8 "2005-02-08T06:52:21Z")
Thanks for the replies. I’d found the online calculators, but I wanted to have all the other numbers I’m playing with calculated, too (points, remaining savings) and have the different percentage loan results all visible on one sheet. **wolf\_meister** : your equation was very helpful. I came across a more detailed version [here](http://www.home-mortgage-guide.com/mortgagecalculators/How_To_Calculate_Amortization_Tables_By_Hand.htm) that works out to be the same as yours. **CurtC** : I’d tried looking up amortization and mortgage in Excel help and couldn’t find those, but they also look like the same equation- thanks. **Civil Guy** : That’s basically it- trying to play with the downpayment and other variables to see what my monthly would be- and looks I may now be able to do it. 🙂 PC ---
**Author:** ![Huerta88](https://avatars.discourse-cdn.com/v4/letter/h/82dd89/32.png) [@Huerta88](https://boards.straightdope.com/u/Huerta88)\ **Post date:** [February 8, 2005, 7:06am UTC](https://boards.straightdope.com/t/can-you-calculate-mortgage-amortization-tabes/288942/9 "2005-02-08T07:06:59Z")
Here is a good site with multiple calculators (and the main site is also quite helpful): [http://www.bankrate.com/brm/calculators/mortgages.asp](http://www.bankrate.com/brm/calculators/mortgages.asp)