How to calculate effective interest rate over multiple investments

Hello there!

I need help to calculate effective interest rate. So I bought steel rods for credit. Because its a credit, the agreed price is higher than a market price. Column A states the dates, when I purchased the steel rods, Column B - the amount in tonnes, Column C - Agreed price, Column D - Market price, Column E - Amount I owe to the shop, Column F - Number of days that credit was given (calculated). On 20.06.2023 the shop is asking me to pay outstanding amounts in full.

I calculated individual interest rates per shipment, but don't know how to calculate for all 5 shipments.

Can you please help my calculate the effective interest?

Welcome to the forum.

Interest over what period? Weekly? Monthly? What is your EXPECTED result (value) calculated manually?

This formatted as a percentage to 2 decimal places will give 14.52%, which is the overall percentage increase:

=(C3-D3)/D3

Is this what you want?

OK - so that's now a lot different to what you asked at the outset!

What would you expect the answer to be for all 5 shipments and how would you calculate it manually? Why 360 and not 365?

That is the problem. I know how I to calculate individually for all 5 shipments (figured after coffee), but I don't know how to calculate for all 5 shipments together...

OK - so it's not an Excel question at all then is it?

EDIT: Grab another coffee and have a read of this: https://www.wallstreetmojo.com/effective-interest-rate/

The thing is, when you come here, we expect you to know HOW to make the calculation and then we help you to turn it into an Excel formula. In this case, you are expecting Excel users to be experts in effective interest calculations - you might get lucky!

I suggest you change the title to: "How to calculate effective interest rate over multiple investments" or something similar to convey the actual nature of your query.

This is it! Thank you, and have a good day!

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