There is a FAQ answering the most common questions here.

1. Are there any tutorials or manuals available?
2. Yes. Although this calculator works like any other financial calculator and you can use any manual, you might find helpful the following links:
Manuals: English, Español, Deutsch ,French
Tutorials: TVM: Time Value Of Money calculations tutorial, NPV and IRR tutorial

3. The numbers are wrong. I use another calculator and I get different numbers What’s going on?
4. Rest assured that the numbers are correct. The calculator it’s used all over the world by financial experts. A financial calculator is not easy machinary and even experts sometimes get it wrong. This is the reason the calculator has an Easy Mode to simplify the functions as much as possible. These are the most common mistakes:

5. Forgetting to set the compounding correctly:
6. Let’ see this easy example. Enter these numbers:
PV = -100
I/Y = 10
N = 1
Then hit “CPT” and FV. A 100, at 10% for 1 period should be 110 right? Is that the number you get?
Yes if your compounding is set to 1 period per year otherwise you will get a different result. (probably 100,83)

This is on the Settings tab under P/Y and C/Y. Set those two numbers to 1 and then it will give you 110. If you want to calculate it by monthly compounding, you would need to set those two numbers to 12 (12 periods per year).

7. Forgetting the right + or – signs.
8. A financial calculator is based on a cashflow format. What this means is that when you put money out, it’s represented with a negative sign. Therefore if you have a savings account that gives you 5% and put \$100 on it, you would enter -100 as the PV value.
The money you receive is positive. Meaning, the 5% you’ll receive will show up as a positive value in the FV number.

9. Changing so many settings that no number makes sense.
10. Playing around with the settings is all good as long as you know what you are doing. If you are totally at lost, just hit the Reset All button in the settings tab and it will go back to the factory default settings.

11. How do you calculate any number? I entered PV, I/Y and so on… now what?
12. The key is to click compute (the “CPT” key) and then the value you want to calculate. So CPT FV will calculate the future value.

13. I see no = sign or “ent”.
14. This is a setting related to RPN (reverse polish notation). It’s very commonly used in HP calculators. Just go to the settings and turn it on/off depending on your preference.

15. I have a bug or some new feature I would like. How do I contact you?
16. You can contact me at the email listed at the bottom of this page. I’ve implemented more than 100 requests that I’ve received by email, so feel free to ask and I’ll surely listen. The calculator is becoming better and better for every request I receive.