You press GRAPH, expect to see your function, and instead get ERR:INVALID DIM. Nine times out of ten this has nothing to do with the equation you typed — it's a leftover stat plot trying to draw data from lists that are empty or invalid. The fix takes about two minutes.
The 2-minute fix: turn off stat plots
- On the error screen, choose
1: Quitto get back to the home screen. - Press
2ndY=to open the STAT PLOT menu. - Choose
4: PlotsOff. - Press
ENTER. The calculator displays "Done". - Press
GRAPHagain. Your function should draw normally.
That's it. PlotsOff switches off every stat plot at once, so you don't have to hunt down which one was the problem.
Why this happens
A stat plot is a scatter plot (or histogram, box plot, etc.) that graphs data straight from lists like L1 and L2. When a plot is turned ON but the lists it points to are empty or invalid, the calculator can't build the plot — so graphing fails with ERR:INVALID DIM before your Y= functions even get a chance to draw.
The classic scenario:
- You (or a classmate who borrowed the calculator) did a stats assignment and turned Plot1 on.
- Later, the lists got cleared — maybe through the memory menu, maybe by resetting for a test.
- The plot's ON/OFF setting persists even after the lists are cleared. So the plot is still on, pointing at lists with nothing in them.
- Next time anyone presses
GRAPH: ERR:INVALID DIM.
This is why the error feels so random. Your equation is fine; a setting from last week's homework is the culprit.
The other cause: asking for an element that doesn't exist
ERR:INVALID DIM also appears when you reference a list or matrix element beyond its actual size. For example:
- L1 holds 5 numbers, but you type
L1(7)— there is no 7th element. - A matrix is 2×3, but you ask for an entry outside those dimensions.
If you hit the error while working with lists or matrices on the home screen (rather than while graphing), this is almost certainly what happened. Choose 2: Goto on the error screen and the cursor will jump to the offending reference so you can see exactly which index is out of range.
To check how long a list really is, press STAT, choose 1: Edit, and scroll to the bottom of the list — or just count the entries. Then fix your index to stay within that size.
Quick reference
| Symptom | Cause | Fix |
|---|---|---|
Error when pressing GRAPH | Stat plot ON with empty/invalid lists | 2nd Y= → 4: PlotsOff → ENTER |
Error on home screen with L1(7)-style input | Index bigger than the list | Use 2: Goto, correct the index |
| Error with matrix entry | Element outside matrix dimensions | Check the matrix size, fix the reference |
If you're seeing a different error entirely — ERR:DIM MISMATCH looks similar but means two lists have different lengths — check the full guide at /error-fixes/error-messages/ to identify which one you've got.
Try the fix right now
Want to practice the fix before your next quiz, or your calculator is in your locker? Use the free online TI-84 calculator — it's a full TI-84 Plus CE in your browser, no download needed. Press 2nd Y=, choose 4: PlotsOff, press ENTER, and graph. Once you've done it once, this error will never cost you more than thirty seconds again.