Combination Sum Calculator

Use this Combination Sum Calculator to Find All the Possible Combinations of the Target Sum.

What is a Combination Sum Calculator?


A combination sum calculator is a mathematical tool that helps you to find all the possible ways to combine a set of numbers to reach a specific target sum.

For example, suppose you have the numbers 2, 3, 4, 5, 6, and 7, and you want to make a sum of 12. Using this combination calculator, you can easily find all the possible unique combinations, which are:

  • 2 + 3 + 7 = 12
  • 2 + 4 + 6 = 12
  • 3 + 4 + 5 = 12
  • 5 + 7 = 12

Real-Time Results

Real-time results, zero clicks — updates 300ms after you stop typing

Handle Large Numbers

Can process large sums with 50+ candidates without freezing

Smart Algorithm Selection

Automatically chooses the best algorithm based on problem complexity

Sum Calculator

combinationsumcalculator.pro

1 + 11 = 12
3 + 9 = 12
5 + 7 = 12
4 + 8 = 12
2 + 4 + 6 = 12
1 + 5 + 6 = 12
1 + 2 + 9 = 12
3 + 4 + 5 = 12
1 + 4 + 7 = 12
1 + 3 + 8 = 12

How to Use this Tool?


1

Enter Target Sum

Target Sum - The number you want to reach

Enter the number you want to reach (for example - 15, 37, or 251 etc). The target sum is also simply known as sum or subset sum.

  • Supports large numbers
  • Smooth UI, even with large datasets
  • Crash free experience on big inputs
Combination Sum Calculator
2

Enter Candidate Numbers

Candidate Numbers - A list of numbers you can use to reach the target sum

The next step is to enter the candidate numbers that can be used to reach the target sum.

For example, if the target sum is 251 and the candidate numbers are (3, 7, 12, 18, 21, 25, 29, 30, 33, 36, 38, 40, 42, 45, 47, 49, 50, 52, 55, 57, 59, 60, 61, 63, 65, 66, 68, 70, 73, 75, 78, 80, 83, 85, 87, 90, 92, 95, 97, 99, 100, 103, 105, 108, 110, 115, 120, 123, 127, 130), the calculator will use these to find all valid unique combinations.

  • Comma-separated Inputs - 3, 5, 7, 9
  • Line-separated Inputs - Can put each number on a new line
  • Mixed Inputs - Can use both comma and new line inputs simultaneously
Combination Sum Calculator
3

View and Download Combinations

After entering the target sum and the candidate numbers, this calculator will find all the possible unique combinations from the candidates numbers which will add up to the target sum.

You can also download all the possible unique combinations in a .txt text document.

  • Instant download
  • Unique combinations
  • First 10,000 possible combinations
Combination Sum

Features


Handles Large Numbers

Can process large target sums like 251 with 50+ candidates without freezing.

Smart Algorithm Selection

Automatically chooses the best algorithm based on problem complexity.

Realtime Results

Combination results are updated in realtime (300ms after you stop typing).

Multiple Input Formats

Supports comma-separated, newline-separated, or mixed formats.

Number Support

This calculator supports both whole numbers and decimal number inputs.

Memory Management

Well optimized to prevent browser crashes and freezes with large datasets.

How This Calculator Works?


Most combination sum calculator freeze or crash when dealing with large numbers because they use naive algorithms with exponential time complexity O(2^n). With just 50 candidate numbers, they attempt to check 2^50 combinations (over 1 quadrillion), which will freeze any browser.

Our calculator solves this problem by intelligently using two well-optimized algorithms - Dynamic Programming for medium problems and Backtracking algorithm for large datasets - ensuring your browser never freezes and deliver results in realtime.

Dynamic Programming

Our first algorithm works like building a staircase - It solves smaller subproblems first and then use them to reach the bigger ones. It creates a table where each step represents a possible sum, storing every way to reach there until we reach the target sum.

Find all combinations systematically
No Repeated Calculations
Time Complexity: O(n x target)
Dynamic Programming

Backtracking Algorithm

Our second algorithm works like exploring a maze, it tries different paths, backtracks when it hits dead ends, and keep going until it finds every solution. It is highly memory efficent, making it perfect for large datasets.

Memory Efficient
Handles Large Numbers
Prevent Your Browser from Crashing
Backtracking Algorithm

Frequently Asked Questions


What is a combination sum calculator?

Combination sum calculator also known as subset sum calculator is a mathematical tool that helps you to find all the possible ways to combine a set of numbers to reach a specific target sum.

What is a target sum?

Target sum or simply sum is the number you want to reach.

What are candidate numbers?

Candidate numbers are the group of numbers you can choose from to create combinations that add up to your target sum.

Why do other calculators freeze or crashes on large numbers?

Most online calculators use naive algorithms with exponential time complexity, which generates billions or trillions of combinations which will freeze any browser.

How does this calculator prevent crashing?

Our calculator solves this crashing problem by intelligently using two well-optimized algorithms - Dynamic Programming for small and medium problems and Backtracking algorithm for large datasets - ensuring your browser never freezes and deliver results in realtime.

How many possible combinations we get to see?

You will get to see first 10,000 possible unique combinations.

Still have questions?

Can't find the answer you're looking for? We'd love to help you out.