Sum of the first n natural numbers
Solve sum of the first n natural numbers with your values and follow each calculation step.
Inputs
Use the units shown—
Enter your values and select Calculate.
Formula & explanation
S = n(n+1)/2
Variables & units
- Last natural number · n
- Numeric value · minimum 1, maximum 1000000
Worked example
1+2+…+100 = 5050.
Assumptions
This sums the integers starting at 1, with no missing terms.
Formula version 1.0.0. JavaScript floating-point arithmetic applies. Results display up to 6 decimal places; stored values retain available precision. Use the units shown.
Practice with an example
Use the default input values to find the answer. The reset icon restores those values.
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