Recently we moved houses. And with the house move, came a brand new mortgage. But as a self-employed person with variable income, I find the steady nature of mortgage payments little hard to digest. So I wanted to know what impact it would have on my mortgage if I make arbitrary extra payments. Unfortunately, I couldn’t find such a calculator. So I made a mortgage calculator with extra payments using Excel. Here is a quick demo of the calculator. Read on if you want to know more or download this.
Mortgage Calculator - DEMO
Download the Mortgage Calculator
Click here to download the Excel Mortgage Payments Calculator (updated with money saved calculation)
How to use this Calculator?
Refer to below illustration and click on the hot spots to understand the process. Essentially, there are 5 things you need to specify or look at when using the template.
- Enter your loan amount
- Enter the loan term (in years)
- Enter the interest rate (APR)
- Specify extra payments in the green column at relevant month rows.
- Look at the chart to understand the impact of your extra payments on the mortgage term.
Enter your mortgage details here.
Enter extra payment amount in relevant month rows.
The chart will show the impact!
How to create such a calculator yourself...
This part of the article discusses the process for constructing such a calculator yourself. Read on (or watch the video tutorial) if you are interested.
The key idea is…
Any extra payments you make bring down the outstanding principal of your loan, thus bringing down the “loan term”.
Step 1: Calculate the monthly (or weekly / fortnightly) payment:
Assuming you have the Loan amount, term & APR in three cells E5, E6 & E7, we can use the PMT() function to calculate the periodic payment.
In my case, let’s say loan is $500,000, term is 20 years and APR (Interest rate) is 5.35% per annum.
Then the Monthly payment would be
=PMT(E7/12,E6*12,E5)
Step 2: Set up amortization schedule
As extra payment will bring down the outstanding loan term, we need to set up an amortization table to see the impact clearly.
So, set up a range of 360 months (or longer if you want to cater for longer mortgages). You can use =SEQUENCE(360) to automatically generate all the months.
Related: Read about SEQUENCE and other Dynamic Array functions in Excel.
Your table should look like this:
- Opening Balance is same as loan amount for month=1. For subsequent months, this will same as previous month’s closing balance.
- Effective term is how long it would take you to pay off the mortgage based on the opening balance, and agreed upon monthly payment (calculated in Step 1) and interest rate (Cell E7). We can use NPER function to get the answer here.
=ROUND(NPER($E$7/12,$E$10,$D13),0) will tell us how many months it is rounded. - Principal Paid is the amount of principal paid in each month. We can get this with the PPMT() function. =PPMT($E$7/12,1,E13,D13)
- Extra Payment is the input column where we can type any extra payments.
- Closing Balance is opening balance minus principal paid minus extra payment.
Complete this table with necessary formulas and fill everything down.
Step 3: Your mortgage will end when the “Eff. Term” is 0.
Go ahead and play with the table by typing some values in the “Extra payment” column. You can see the effective term reducing.
We can visualize the impact with a nice chart (requires some extra work) like this:
Do check the download workbook for details on how the chart is setup.
Video Tutorial - I made a mortgage calculator in Excel
Watch below video to understand how I made the mortgage calculator with flexible payments. If you prefer to see it on YouTube, click here.
Looking for an Amortization Schedule instead?
If you want to make a regular amortization schedule with Excel, check out Excel Amortization Schedule template.
More Financial Models with Excel
If you want to learn more about setting up calculators, models or business systems with Excel, check out below tutorials & examples:
Nest Egg Calculator using Power BI
Interactive Mortgage Calculator to know how much you can borrow (with Excel)
Sara’s Copy Shop – Break even analysis and what-if modeling in Excel [Videos]
Using IRR with Data Tables – Modeling Cash-flow Scenarios in Excel
Doing Cost Benefit Analysis in Excel – a case study
22 Responses to “Formula Forensic No 019. Converting uneven Text Strings to Time”
Why not let the TIME function take care of the math:
=TIME(LEFT(TEXT(A1,"000000"),2),MID(TEXT(A1,"000000"),3,2),RIGHT(TEXT(A1,"000000"),2))
I was going to point out the same thing, except to note that useing the time function and doing the divide method are not interchangeable.
I have spent hours investigating a spreadsheet working with a couple of years worth of hourly data, and found that the reason things weren't working is because the rounding on the divide method is only close to the correct time values. In order to have it work for comparisons, (like sub-totaling by time value, or pivoting) you MUST use the TIME function.
Great use of the TEXT function, Hui. I will be using this concept for sure.
Why not just.
=TEXT(A1,"00\:00\:00")*1
Regards
Elegant!
Hi Elias,
I tried to use your formula. But, it doesn't seem to work for me. I am getting an error message "The formula you typed contains an error". It seems I have the problem in using \: in the format. How can I overcome this?
Thanks
Manick, it isn't the /: that causes the problem. If you copy/paste it, you're getting “'s instead of the actual quotation marks that Excel uses. Change the quotation marks by deleting from the pasted formula and retype them.
Hi Manick...
use this alternate formula :
=1*TEXT(A1,"00"":""00"":""00")
note twice double quote each side of :
@Manick,
Did you copy the formula and pasted in Excel or did you typed? Also, do you use , or ; as separator of arguments?
Regards
@Elias: I had no problem using your formula, in fact, I have used your method to convert a number such as 20120419 to an Excel date using =TEXT(A1,"0000\/00\/00")*1. Thanks for posting.
@Joe: For date convertion you can use this as well.
=TEXT(A1,"00-00-00")*1
Regards
Sweet! It appears this also works with =TEXT(A1,"0-00-00")*1. I come from the old days when you counted every byte. I also like to try an make formulas as small as possible for the fun of it 🙂
Elias's suggestion is the simplest, but here is yet another way with TIME and MOD functions...
=TIME(MOD(A2/10000,100),MOD(A2/100,100),MOD(A2,100))
Since the seconds appear to always be 0, why not simply the input to minutes and above and save yourself the trouble of typing those zeroes...
0 => 0:00
1 => 1:00
10 => 10:00
100 => 1:00:00
etc.
Then just use this formula...
=TEXT(A1,"0\:00\:")*1
@ Rick, the numbers to convert are no typed, they are imported. Then your formula will return the wrong result.
Regards.
Hmm! My formula lost some backslash-zero combinations (two of them to be exact). The formula was supposed to be this...
=TEXT(A1,"0\:00\:\zero\zero")*1
where the words "zero" should actually be the number 0. Another way to write the formula is this...
=TEXT(A1,"0\:00\:""00""")*1
Hi Master,
While writing the formulae you have considered only upto "seconds factor" . I think you should take the centi-seconds factor also to achieve best results. Please look into it and rectify the problem...?
For Example.
In horse racing timings are noted in minute, seconds and centi-seconds, like if a horse finished in 70 seconds over a scurry of 1200 metres, is noted as 1.10 min. Nowadays it is noted in centi-seconds everywhere, like 70.00 if you want to convert it to centi seconds (should multiply by 100) = 7000 centi seconds. If you put this figure into your formula as a general number (7000) it will return as 1:10:00. As per your formula, it should be taken as 1 hour 10 seconds 0 minutes. However for a racing enthusiast like me it can be taken as 1 minute 10 seconds also.
Just look what happens if we race goers use this figure as 7000 centi seconds in your formulae, it will correctly show as 1 minute 10 seconds(?) Suppose a horse finishing over a 1200m in 70.60 seconds or in racing terms written as 1.10.60 mins, where 1 minute 10 seconds, & 60 centi-seconds can be counted as 7060, if you put this figure in the formula it will return as 1 minute 11 seconds, that is correct.
My point is if you can incorporate Centi Seconds in the formulae, it would be of great help to us also.
Thanks and regards.
Rajagopal (Mumbai)
Awesome techniques !
I tried with 235960 just to see if it will fail but this is great.
Although a little longer, this too work:
=CHOOSE(LEN(A2);A2/(24*3600);A2/(24*3600);LEFT(A2;1)/(24*60) + RIGHT(A2;2)/(24*3600);LEFT(A2;2)/(24*60) + RIGHT(A2;2)/(24*3600);LEFT(A2;1)/24 + MID(A2;2;2)/(24*60) + RIGHT(A2;2)/(24*3600);LEFT(A2;2)/24 + MID(A2;3;2)/(24*60) + RIGHT(A2;2)/(24*3600))
Converting uneven Text Strings to Time I have imported some data that comes in as a number that I need to convert to h:mm.
Just come across this while googling
find interesting challenge and come up with this
=TEXT(TEXT(SUBSTITUTE(A1,RIGHT(A1,1),""),"000000"),"00\:00\:00")
I need to convert a string of numbers representing average minutes, to reflect correct time values. For example, the numbers below currently represent 5.79 minutes, 15.82 minutes, etc.
I need to convert these values to their correct corresponding value within time parameters. So 5.79 would be something close to 5 minutes and 45 seconds.
5.79
15.82
3.92
12.40
6.70
3.62
I know there has to be a way to compute this in Excel, it can do anything, I believe!
Thank you for any and all assistance~
@Renee... You can use a formula like this. Assuming A1 has the minutes.seconds,
=INT(A1) + MOD(A1, 1)*0.6
If you want to see it in 5 minutes 45 seconds format, use
=INT(A1) & " mins " & ROUND(MOD(A1, 1)*0.6,2) & " secs"