Math

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Consecutive Integers Calculator.

List the first n consecutive integers from a starting value and calculate their sum.

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01

Set your values

Results update as you type.

First integer: 1

First integer

1.000000
Last integer: 10

Last integer

10.000000
Count: 10

Count

10.000000
Sum: 55

Sum

55.000000

Results update automatically as you type.

Use Cases

Quickly sum a range of integers

Instead of adding a long list manually, enter the starting number and the count to get the sum instantly. Useful for checking homework or planning sequences.

Example: Start at 1, count 100 → sum = 5050

Explore number patterns

See how consecutive integers behave with different starting points, including negatives, to understand arithmetic sequences and sums.

Example: Start at -5, count 10 → sum = -5

Frequently Asked Questions

How do I use the Consecutive Integers Calculator?
Enter a starting integer (positive, negative, or zero) and the count of integers you want. The calculator lists the first 'count' consecutive integers beginning from your starting value and computes their total sum.
Can the starting integer be negative?
Yes, the starting integer can be any integer, including negative numbers and zero. For example, starting at -3 with a count of 5 gives -3, -2, -1, 0, 1, and the sum is -5.
What does 'Count' mean in this calculator?
Count is the number of consecutive integers you want to generate. For instance, if you start at 10 and set count to 4, you get 10, 11, 12, 13, and their sum is 46.

Tips & Common Mistakes

Tips

  • Double-check that your count is a positive whole number; the calculator expects a count of integers, not a range endpoint.
  • Use a negative starting integer to see how sums change when the sequence crosses zero.
  • For large counts, the calculator saves time and avoids arithmetic errors—try it with count = 1000.
  • Remember that the sum of consecutive integers from 1 to n is n(n+1)/2; you can verify the calculator's result with this formula.

Common Mistakes to Avoid

  • Entering the ending value instead of the count. The calculator asks for the number of integers, not the last integer.
  • Assuming the starting integer must be positive—it can be any integer, including zero or negative numbers.
  • Forgetting that the count includes the starting integer itself. For example, count = 5 starting at 2 gives 2,3,4,5,6 (five numbers).

Last updated: August 13, 2026