Summation Calculator
Add up series of numbers, squares or cubes over any range with a custom step.
Interval between terms.
Sum
55
Sum of terms from 1 to 10
Number of terms
10
Step of 1
Adds every term from the start value up to the end value at the given step. Sums of consecutive integers use n(n+1)/2, squares use n(n+1)(2n+1)/6 and cubes use [n(n+1)/2]².
Summation Calculator on True Calculator gives you an instant, accurate answer with no sign-up and no app install. Add up series of numbers, squares or cubes over any range with a custom step. Every result shows the formula and a worked example so you can verify the calculation yourself, and all values are computed in your own browser — your numbers never leave your device.
Popular uses: summation calculator · sum of series · sum of squares
Reviewed by the True Calculator team · Last updated: August 2026
How We Calculate
This calculator uses standard mathematical formulas — the same ones taught in school and used in exams — verified by our team. All calculations are performed instantly in your browser using JavaScript, so no data is sent to any server.
The formulas follow standard mathematical definitions and conventions used in textbooks and by educational boards. Results are rounded transparently and shown with the exact formula on this page.
When to Use This Calculator
Use the summation calculator whenever a problem asks for the total of a number series — the first n natural numbers, sums of squares or cubes, arithmetic series with a common difference, or sigma-notation questions from school and JEE mathematics. Indian students preparing for board exams and competitive tests meet series sums constantly, and this tool verifies both their manual work and the standard formulas in seconds. Finance users add up monthly expenses over a range, developers estimate cumulative loop work, and statisticians total squares of deviations for variance problems. Plain mode handles any integer range with a custom step, while power mode covers squares and cubes directly, making it a general-purpose accumulator that removes arithmetic errors from any repetitive addition.
How to Use This Calculator
- Step 1: Choose plain sum or the power mode — squares, cubes or higher powers.
- Step 2: Enter the starting number and the ending number of the range.
- Step 3: For plain sums, set a step; for example 2 to sum only even numbers.
- Step 4: Read the total of the series from the result card.
Worked Example
A student in Kolkata adds the first 10 natural numbers to verify the formula n(n+1)/2. Entering 1 to 10 with step 1 gives 55, matching the formula exactly. Stepping by 2 from 2 to 10 sums the even numbers 2 + 4 + 6 + 8 + 10 = 30. The power mode sums squares: 1² + 2² + 3² + 4² = 30, while 1³ + 2³ + 3³ = 36. The classic total of 1 to 100 comes out as 5050, the sum Gauss famously computed in seconds.
Tips and Common Mistakes
- •Tip 1: Use a step of 2 to sum only evens or only odds — start on the parity you want.
- •Tip 2: The sum of the first n natural numbers is n(n+1)/2; use the calculator to confirm any formula quickly.
- •Tip 3: Power mode accepts powers from 1 to 6, covering squares and cubes used in board exam series problems.
- ✗Mistake 1: Reversing the range — the calculator expects the start to be no larger than the end and returns a hint otherwise.
- ✗Mistake 2: Entering a zero or negative step, which would never finish the loop; the calculator refuses instead.
Frequently Asked Questions
What can the summation calculator add up?
It adds every term in a range with a chosen step — plain numbers, squares or cubes. For example, numbers from 1 to 10 step 1 sum to 55, squares from 1 to 10 sum to 385, and cubes from 1 to 5 sum to 225.
Why is the sum of 1 to 100 always 5050?
Because of Gauss's pairing trick: 1 + 100 = 101, 2 + 99 = 101, and so on, giving 50 pairs of 101. The formula n(n+1)/2 = 100 × 101 / 2 = 5050 confirms it. The calculator uses the same mathematics instantly.
What does the step option do?
The step skips terms in the range. With start 1, end 10 and step 2, the calculator adds 1, 3, 5, 7 and 9 to get 25 — the odd numbers only. Step must be a whole number greater than zero.
Can I sum squares or cubes?
Yes, choose 'squares' or 'cubes' from the dropdown. Sum of squares from 1 to n uses n(n+1)(2n+1)/6, and sum of cubes equals [n(n+1)/2]² — both are standard results asked in Indian school mathematics and aptitude tests.
Why is the start-to-end range required?
A series needs a defined range. If the start is larger than the end, the calculator returns a hint instead of a negative or empty result, so your answer is always meaningful.
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