TVM Solver on TI-84 — Finance Problems Step by Step

Compound interest, loan payments, savings goals — the TI-84's TVM Solver (Time Value of Money) handles all of them without a single formula. This guide explains every variable, the sign convention that trips everyone up, and two fully worked examples you can replicate keystroke for keystroke.

Opening the TVM Solver

Press APPS
Choose 1: Finance
Choose 1: TVM Solver

You'll see a screen of variables. You fill in everything you know, then solve for the one you don't.

What each variable means

Variable	Meaning	Common mistake
N	Total number of payments/periods	Entering years instead of months
I%	Annual interest rate, as a percent	Entering 0.065 instead of 6.5
PV	Present value (amount now)	Wrong sign
PMT	Payment per period	Wrong sign, or wrong period
FV	Future value (amount at the end)	Forgetting to set it to 0 for a paid-off loan
P/Y	Payments per year	Leaving it at 1 for a monthly problem
C/Y	Compounding periods per year	Usually fine — it auto-matches P/Y when you set P/Y
PMT: END BEGIN	When payments occur	Leave on END for almost every textbook problem

Two rules do most of the work:

I% is the annual rate as a percent (6.5, not 0.065 and not the monthly rate). The calculator divides by C/Y internally.
N counts periods, not years. Monthly payments for 5 years → N = 60.

The sign convention (cash flow direction)

The TVM Solver thinks in cash flows from your pocket's point of view:

Direction	Sign	Examples
Money you pay out	Negative	Deposit into savings, loan payment
Money you receive	Positive	Loan money handed to you, savings balance you withdraw

If your answer has a surprising sign — or the solver returns an error — check the signs first. A deposit is negative; the future balance you get back is positive.

How to solve for a variable

Fill in every known value, pressing ENTER or the down arrow after each
Move the cursor onto the variable you want to find
Press ALPHA ENTER (the SOLVE function)
A small square appears next to the solved variable, marking it as the computed result

Worked Example 1: Savings with compound interest

Question: You deposit $5,000 in an account earning 4% annual interest, compounded monthly. How much is it worth after 10 years?

Fill in the TVM Solver:

N = 120          ← 10 years × 12 months
I% = 4
PV = -5000       ← you pay the deposit out, so negative
PMT = 0          ← no monthly additions
FV = 0           ← this is what we'll solve for
P/Y = 12
C/Y = 12
PMT: END

Move the cursor to FV and press ALPHA ENTER.

Result: FV = 7454.163817

The account grows to about $7,454.16. (Sanity check: 4% simple interest would give $7,000; monthly compounding beats that, as expected.)

Worked Example 2: Car loan payment

Question: You borrow $20,000 for a car at 6.5% annual interest, repaid in 60 equal monthly payments. What is the monthly payment?

N = 60           ← 5 years of monthly payments
I% = 6.5         ← the annual percent, NOT 0.065
PV = 20000       ← the bank hands you money: positive
PMT = 0          ← solve for this
FV = 0           ← the loan is fully paid off at the end
P/Y = 12
C/Y = 12
PMT: END

Move the cursor to PMT and press ALPHA ENTER.

Result: PMT = -391.3202355

The payment is about $391.32 per month — negative because it flows out of your pocket. Total paid: 60 × 391.32 = $23,479.20, so this loan costs about $3,479 in interest.

Common mistakes checklist

I% as a decimal. Entering 0.065 instead of 6.5 computes a loan at 0.065% interest — the payment comes out around $334, quietly wrong. I% is a percent.
N in years. N = 5 with P/Y = 12 means five payments, not five years. Always N = years × P/Y.
Missing negative sign. With PV and FV (or PV and PMT) given the same sign, the equation may have no solution and the solver throws ERR:NO SIGN CHNG. One side of the transaction must be negative.
Stale values from the last problem. The TVM screen remembers old entries. Walk through every field each time — especially FV and PMT.
P/Y left at 1. For a monthly problem this treats each payment as annual, inflating everything. Set P/Y first; C/Y follows automatically (change C/Y afterward only in the rare problem where compounding and payment frequencies differ).

Writing answers on exams

State the variables, not just the result: "Using TVM Solver with N = 60, I% = 6.5, PV = 20000, FV = 0, P/Y = C/Y = 12, solving for PMT gives −391.32, so the monthly payment is $391.32." That sentence shows the setup, the tool, and the interpretation — the same show-your-inputs habit that earns credit on stats questions like normalcdf and invNorm.

Practice right now

Open the free online TI-84 calculator — a complete TI-84 Plus CE in your browser, no download or install — press APPS 1 1, and reproduce both examples. If your screen shows FV = 7454.16 and PMT = −391.32, your TVM workflow is solid. Then remix example 2: what happens to the payment at 72 months instead of 60?