How to use the number of terms in arithmetic sequence calculator
Count how many terms an arithmetic sequence has from its first term, last term and common difference. Enter first term, last term, common difference in the fields above; the number of terms, sum of all terms are computed instantly and plotted on the chart so you can see how the answer changes.
Common searches this calculator answers include “how many terms in sequence”, “count terms arithmetic”, “number of terms between two values”, “calculate number of terms in arithmetic sequence”, “find number of terms”.
Formula
Variables
- first — First term
- last — Last term
- d — Common difference
Worked example
With first term = 3, last term = 99, common difference = 3, the calculator gives number of terms ≈ 33; sum of all terms ≈ 1,683.
Frequently asked questions
What is the number of terms in arithmetic sequence calculator used for?
Count how many terms an arithmetic sequence has from its first term, last term and common difference. It helps with questions such as “how many terms in sequence”, “count terms arithmetic”, “number of terms between two values”.
What is the formula for the number of terms in arithmetic sequence calculation?
Number of terms = (last-first) / d+1. Sum of all terms = [Number of terms] × (first+last) / 2. Here first is first term, last is last term, d is common difference.
What inputs do I need for the number of terms in arithmetic sequence calculator?
You need first term, last term, common difference. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use the number of terms in arithmetic sequence calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the number of terms in arithmetic sequence result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.