Limit Calculator
Estimate the limit of a function as x approaches a value or infinity. See the full two-sided approach table and whether the limit exists at all.
Approach table
| h | x = a − h | f(a − h) | x = a + h | f(a + h) |
|---|---|---|---|---|
| 1e-1 | -0.1 | 0.998334166 | 0.1 | 0.998334166 |
| 1e-2 | -0.01 | 0.999983333 | 0.01 | 0.999983333 |
| 1e-3 | -0.001 | 0.999999833 | 0.001 | 0.999999833 |
| 1e-4 | -0.0001 | 0.999999998 | 0.0001 | 0.999999998 |
| 1e-5 | -0.00001 | 1 | 0.00001 | 1 |
| 1e-6 | -0.000001 | 1 | 0.000001 | 1 |
| 1e-7 | -1.000000e-7 | 1 | 1.000000e-7 | 1 |
| 1e-8 | -1.000000e-8 | 1 | 1.000000e-8 | 1 |
f(0) has no value at that point, which is exactly the situation limits exist to describe — the limit can still exist even though the function has a hole there.
This is a numerical estimate from sampled values, not a symbolic proof. Very flat, oscillating or floating-point-sensitive functions can mislead it, so always sanity-check the table.
What is the Limit Calculator?
The ByteTools Limit Calculator estimates lim(x→a) f(x) numerically. It evaluates the function at a ± 10⁻¹ all the way down to a ± 10⁻⁸ and prints the whole approach table, so you can watch the behaviour from both sides instead of taking a single answer on trust.
- Full two-sided approach table from 10⁻¹ down to 10⁻⁸
- Distinguishes a finite limit, ±∞ and 'does not exist'
- Shows both one-sided values when they disagree
- Handles limits as x approaches positive or negative infinity
- Tells you whether f(a) itself is defined, so you can spot removable holes
- Runs entirely in your browser with nothing uploaded
How to use the Limit Calculator
- 1
Enter the function in the f(x) box, for example sin(x)/x or (x^2-1)/(x-1).
- 2
Choose whether x approaches a finite number, +∞ or −∞.
- 3
If you picked a finite value, type it into the 'Value of a' box.
- 4
Read the reported limit, then check the approach table to see how the values behave from each side.
- 5
Click Copy limit to save the result.
About the Limit Calculator
The ByteTools Limit Calculator estimates lim(x→a) f(x) numerically. It evaluates the function at a ± 10⁻¹ all the way down to a ± 10⁻⁸ and prints the whole approach table, so you can watch the behaviour from both sides instead of taking a single answer on trust.
It reports a limit when both sides settle on the same value, ±∞ when the values grow steadily without bound, and 'does not exist' when the left and right sides disagree — showing you both one-sided values so you can see exactly why. Limits as x → ±∞ are handled by walking x out to 10⁸.
This is a numerical estimate from sampled values, not a symbolic proof, and oscillating functions can mislead it — the table is there so you can judge for yourself. Everything runs locally in your browser and nothing is uploaded.
Frequently asked questions
How do you find the limit of a function?
You examine what the function's values approach as x gets close to the target, from both sides. If both sides head to the same number, that number is the limit. This calculator does exactly that numerically and prints the table so you can follow the approach.
What does it mean when a limit does not exist?
It means the function does not settle on a single value near that point. Most often the left-hand and right-hand limits differ, as with a jump discontinuity. The calculator shows both one-sided values so you can see the disagreement directly.
Can a limit exist if the function is not defined at that point?
Yes, and that is the whole point of limits. sin(x)/x has no value at x = 0 yet its limit there is 1. The calculator tells you whether f(a) itself is defined separately from what the limit is.
Why does the limit calculator say the result is inconclusive?
The sampled values did not settle to one number and did not grow steadily towards infinity. That usually means the function oscillates near the point, or floating-point rounding is dominating. Read the approach table to see which is happening.
How does the calculator handle limits at infinity?
It evaluates the function at x = 10, 100, 1000 and onwards to 10⁸, then reads the trend from the tail of that sequence. Rational functions and most textbook examples settle quickly and give a clean answer.
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