C++ Program To Find Simple Interest Last Updated : 23 Jul, 2025 Comments Improve Suggest changes Like Article Like Report Try it on GfG Practice What is 'Simple Interest'? Simple interest is a quick method of calculating the interest charge on a loan. Simple interest is determined by multiplying the daily interest rate by the principal by the number of days that elapse between payments. Simple Interest formula: Simple interest formula is given by: Simple Interest = (P x T x R)/100 Where, P is the principal amount T is the time and R is the rate Examples : Example 1: Input: P = 10000 R = 5 T = 5 Output: 2500 We need to find simple interest on Rs. 10,000 at the rate of 5% for 5 units of time. Example 2: Input: P = 3000 R = 7 T = 1 Output: 210Recommended PracticeSimple InterestTry It! The formula to calculate the simple interest is: simple_interest = (P * T * R) / 100 where P is the principal amount, T is time & R is the rate of interest. Below is the implementation of the above example: C++ // C++ program to find simple interest // for given principal amount, time // and rate of interest. #include<iostream> using namespace std; // Driver code int main() { // We can change values here for // different inputs float P = 1, R = 1, T = 1; // Calculate simple interest float SI = (P * T * R) / 100; // Print the resultant value of SI cout << "Simple Interest = " << SI; return 0; } Output: Simple Interest: 0.01 Time complexity: O(1).Auxiliary space: O(1). Comment More info K kartik Follow Improve Article Tags : C++ Programs C++ C Basic Programs Explore C++ BasicsIntroduction to C++ Programming Language3 min readData Types in C++7 min readVariables in C++4 min readOperators in C++9 min readBasic Input / Output in C++5 min readControl flow statements in Programming15+ min readLoops in C++7 min readFunctions in C++8 min readArrays in C++8 min readCore ConceptsPointers and References in C++5 min readnew and delete Operators in C++ For Dynamic Memory5 min readTemplates in C++8 min readStructures, Unions and Enumerations in C++3 min readException Handling in C++11 min readFile Handling through C++ Classes8 min readMultithreading in C++8 min readNamespace in C++5 min readOOP in C++Object Oriented Programming in C++8 min readInheritance in C++10 min readPolymorphism in C++5 min readEncapsulation in C++4 min readAbstraction in C++4 min readStandard Template Library(STL)Standard Template Library (STL) in C++3 min readContainers in C++ STL3 min readIterators in C++ STL10 min readC++ STL Algorithm Library2 min readPractice & ProblemsC++ Interview Questions and Answers1 min readC++ Programming Examples7 min read Like