Today, lets learn OFFSET formula.
What is OFFSET and why bother using it?
OFFSET formula gives us reference to a range, from a given starting point with given height and width in cells.
OFFSET formula syntax
OFFSET formula looks like this:
=OFFSET(starting point, rows to move, columns to move, height, width)
- Starting point: This is a cell or range from which you want to offset
- Rows & columns to move: How many rows & columns you want to move the starting point. Both of these can be positive, negative or zero. More on this below.
- Height & width: This is the size of range you want to return. For ex. 4,3 would give you a range with 4 cells tall & 3 cells wide.
And yes, All the arguments to OFFSET can be references to other cells. That means, you can write =OFFSET(A1,D1,D2,D3,D4) which will refer to a range
- Starting from A1
- Offset by D1 rows & D2 columns
- having the size of D3 rows & D4 columns
See below examples to understand the formula better.
OFFSET formula examples
Why use OFFSET?
Why not write a reference like A1:C4 directly?
Here are a few reasons why,
- Dynamic ranges: Reference like A1:C4 always refers to the range A1:C4. ie it is static. But sometimes, we want our ranges to be dynamic. This is required because our data is changing (every month new row is added, every time we launch a product new column is added etc.)
- We don’t know the exact address: Sometimes, we don’t know what our ranges actual address is. Rather, we just know it is starting from a certain cell etc. In such situations OFFSET is useful.
Understand OFFSET formula – Interactive Workbook
Since OFFSET formula is somewhat tricky to get, I created an interactive workbook so that you can understand how it works. When you input all the 5 parameters, the workbook highlights the range that your OFFSET will give. After playing with it for a few minutes, you will understand the formula better.
Practical use for OFFSET – Average of latest week
Lets say we monitor quality of a plant producing purple puppets. One of the KPIs we monitor is % of rejected puppets. We have been tracking the % of rejects by day in a spreadsheet that looks like this:
So how do we calculate average of latest week?
Assuming the values are in range C3:C18, we can write =AVERAGE(C12:C18)
BUT, WE NEED TO CHANGE THIS FORMULA EVERYDAY!!!
Even puppets would find that boring.
By using the OFFSET awesome sauce, we can write the AVERAGE formula once and forget about it.
=AVERAGE(OFFSET(C3,COUNTA(C3:C300)-7,0,7,1))
Lets break-apart this formula and understand
- To calculate latest week’s average, we need to go all the to the last data point and then get 7 rows from it and average those values.
- This is where COUNTA(C3:C300) – 7 comes in to picture. It counts how many values are there in column C and then subtracts 7 from it.
- The OFFSET would then starting point from C3 to latest week’s starting point.
- To know how this formula works, watch below demo.
OFFSET limitations
While offset formula can return with a dynamic range when you beckon, it does have few limitations:
- OFFSET formula is volatile: In plain English it means, whenever there is any change in your workbook, OFFSET formula is recalculated, thus keeping Excel busy a tiny bit longer. This is not an issue if you use OFFSET formula in a small workbook. But when you use lots of OFFSET formulas in large workbooks, you will end up cursing Excel as it takes too much time to recalculate.
- OFFSET formulas are tricky to debug: Because the references are dynamic, debugging a workbook with lots of OFFSETs can get tricky quickly.
Alternatives to OFFSET formula
There 2 fine alternatives to OFFSET formula.
- Use Excel Tables: Since Excel 2007, we can create tables from structured data and write formulas, create charts that refer to dynamic ranges with ease. Click here to know more about tables.
- Use INDEX formula: Although not exactly same as OFFSET, INDEX formula can also be used to generate dynamic range references. Plus, INDEX is a non-volatile formula, so it wont keep Excel busy unnecessarily. Know more about INDEX formula.
Do you use OFFSET formula?
For most of my dynamic range needs, I rely on tables or INDEX formula. I use OFFSET formula when I have to calculate values like average of latest week. In such cases OFFSET is an elegant solution.
What about you? Do you use OFFSET formula? In which situations do you use it? Please share your tips & examples with us using comments.
Know More about OFFSET
Check out below examples to understand OFFSET formula better:
- Calculations: Sum of values between 2 dates | Moving averages | Average of closest numbers| More…
- Modeling: Calculate IRR of dynamic ranges | Manage scenario analysis
- Charting & Dashboards: Dynamic range charts | Top x chart | Analyzing large datasets | KPI dashboards
- Validations & Pivots: Dynamic Data Validation | Dependent Drop downs | De-duplicate & Sort data
- And many more uses of OFFSET
20 Responses to “Mortgage Calculator with Extra Payments – Excel Download”
Kia ora Chandoo, thanks for this wonderful template brother. How can I modify this/ or do you have a similar template for a fortnightly
payment? Thank you
Morena Rayd. You can adjust the multiplier / divider to 26 (I think it was set to 12) to see fortnightly details. Watch the companion video to understand the steps / logic.
It is very simple and easy to use. Is user interface is attractive. It is very helpful and beneficial for calculations.
This is great, thanks a lot!
I think there is an error in the "You save X $ in interest". If i dont put any extra payment, it still says that I will save 19k in interest rate.
I too realized this problem. I will post an update once I fix the error.
Updated on 11-Sep: I fixed the problem with "interest saved" calculation. Turns out there was an internal bug in cumipmt function in Excel that reports incorrect values. Something new!
Please use the link above to re-download the correct file.
Hi Chandoo, do you have a template that will make changes to figures going forward if the interest rate changes part way through the loan? Thank you for your help.
I wanted calculator which can consider floating interest rate, can you please advise how to get that?
I love your tutorial. If I am making weekly acelerated mortgage payments, how to I account for that in the Eff term?
Thank yo so much,
Christine
Hi Chandoo. I want an excel template where I can have my favourite stocks listed for which the prices changes on a dynamic basis every day as per the market. I mean a sheet which is linked to NSE for price changes and other changes like daily low, Daily high, Yesterday closing, last 10 day range, 52 week high, 52 week low, one month high, one month low, one week high and one week low etc
The excel is awesome but I am getting #NAME? error with the field 'Old Interest Paid' and subsequently Original Interest and Money saved. Can you tell me how to fix that. I am trying to check if I should complete my loan by the extra payments or instead invest the same amount elsewhere
#NAME error could mean your Excel doesn't have one of the functions I am using. Can you tell me what version you are using? If I am not mistaken, this file requires Excel 365.
Hi Chandoo, I am also getting the same error. I am using Office 2019. Would you be able to recommend a fix for this?
Regards,
How do you change the dollar to rupees for whole sheet to match indian currency
You can select the values and apply rupee formatting from cell formatting options.
Hey Chandoo,
Thank you for making the excel spreadsheet! It is great, but there another, little known money saving action that you can take to DRAMATICALLY reduce your total interest owed on your mortgage allowing you to pay it off 40% to 60% faster. I am going to share with you for free. It's called recasting your mortgage, which is a form of re-amortizing the interest that you owe on your loan by paying the the bank an early payment of $10,000 or more. The bank will modify your loan to cancel the original interest that you owe, and recalculate the total interest based on the new lower loan loan amount for the remaining term of the loan, instead of the original loan amount. This pays off the most expensive section of interest on your loan which is the next owed interest, instead of cancelling the interest at the end of your loan. Your charts show the interest being canceled on the last payments, however the interest can be canceled on your next upcoming portion of the loan, but keeps the ending date the same. However, the result of recasting the loan is you, pay the loan off 2 or 3 times faster, by paying off the portion of the loan with the highest interest cost. I am wondering if you can build a excel spreadsheet that shows this for me? I will pay you for making it. I am a mortgage loan officer and would like to use it to help my clients see the impact of paying off their loans this way. Thank you for considering this!
HI Chandoo.
Excellent sheet i watched your video and tried to edit sheet to suit my current mortgage however i cant get it to work. I am trying to set it to weekly payments.
I edited the monthly payments to =PMT(E7/52,E6*52,E5)
eff.term =ROUND(NPER($E$7/52,$E$10,$D13),0)
principal term to =PPMT($E$7/52,1,E13,D13)
cb w/o to =IF(C13=1,$E$5,J12)+PPMT($E$7/52,C13,$E$6*52,$E$5)
and interest paid to =IPMT($E$7/52,1,E13,D13) but i cant edit the arrays to increase the range to 1560 from 360, so i just added the numbers in and that worked for the array on the left but the old interest paid array im stuck. And the graph well the graph is useless now and i have no idea how to fix that. no idea at all.
Any help would be great.
Cheers
To change the NUMBER OF ROWS, go to cell C13 and change the formula to
=SEQUENCE(E6*52)
The chart won't auto-adjust. So you need to adjust the chart's source data range to capture all rows.
Hey man, I really appreciate your contribution, this template is awesome, I am sure it will help me to plane my financial life, and also to pay debts earlier and create wealth.
Thank you!!!
how do i edit this to use months instead of years for term? i have a 90 month loan (7.5 years) that i am trying to use with this and it forces me to use 7 or 8 in years.