Online Calculators

Singh Habitat provides simple and free online calculators for everyday calculations.

How to Use Our Calculators

Singh Habitat provides free online calculators designed to make common calculations easier to understand. Choose a calculator, enter the required information and review the result.

How to Calculate GST

Enter the amount and applicable GST rate to calculate the tax amount and total price. For example, 18% GST on ₹1,000 is ₹180, making the total ₹1,180 when GST is added.

Try the GST Calculator

How to Calculate Age

Enter your date of birth to calculate your age in years, months and days. Check that the date entered is correct for a meaningful result.

Try the Age Calculator

How to Calculate BMI

Body Mass Index is calculated by dividing weight in kilograms by height in metres squared. For example, 60 kg divided by 1.65 × 1.65 gives a BMI of approximately 22.04. BMI is a screening measure, not a diagnosis.

Try the BMI Calculator

How to Calculate a Percentage

Divide the part by the total and multiply by 100. For example, 25 out of 200 is (25 ÷ 200) × 100, which equals 12.5%.

Try the Percentage Calculator

Accuracy and Limitations

Calculator results depend on the information entered and the formulas used. Review your inputs before relying on a result. For important financial or tax decisions, verify applicable rules and rates with an appropriate official source.

BMI results provide general screening information and should be interpreted in context. They do not replace professional medical advice or an individual health assessment.

PRACTICAL EXAMPLES

Real-Life Calculation Examples

Learn how to solve everyday calculation problems with simple formulas and step-by-step examples.

GST Calculation Example

Suppose a product costs ₹1,000 before GST and the applicable GST rate is 18%.

Product price: ₹1,000

GST rate: 18%

GST amount: ₹1,000 × 18 ÷ 100 = ₹180

Total price: ₹1,180

This example assumes GST is added to the original price. The applicable tax rate depends on the product or service and relevant rules.

Try GST Calculator →

Percentage Calculation Example

Suppose a student scores 75 marks out of 100. To calculate the percentage:

Marks obtained: 75

Total marks: 100

Percentage = (75 ÷ 100) × 100

Result: 75%

The same formula can be used for test scores, survey results and many other everyday calculations.

Try Percentage Calculator →

BMI Calculation Example

Suppose an adult weighs 60 kg and is 1.65 metres tall. BMI is calculated using weight and height.

Weight: 60 kg

Height: 1.65 m

BMI = 60 ÷ (1.65 × 1.65)

Result: Approximately 22.04

BMI is a screening measure, not a diagnosis. Its interpretation depends on factors such as age and individual circumstances.

Try BMI Calculator →

Age Calculation Example

Age is calculated by comparing a person's date of birth with a selected reference date.

Date of birth: 15 January 2000

Reference date: 15 January 2025

Result: 25 years

If the reference date falls before the birthday in a given year, the completed age in years is one less.

Try Age Calculator →
LEARN THE METHOD

Calculation Formulas Explained

Understanding a formula helps you check the result and apply the same method to different numbers.

01

Percentage Formula

Percentage = (Part ÷ Whole) × 100

Divide the part by the total and multiply by 100. For example, 30 out of 120 is (30 ÷ 120) × 100 = 25%.

Calculate a Percentage →
02

GST Amount Formula

GST Amount = Original Price × GST Rate ÷ 100

For an original price of ₹2,000 and an assumed GST rate of 5%, the GST amount is ₹100. The total price after adding GST is ₹2,100.

Calculate GST →
03

Body Mass Index (BMI) Formula

BMI = Weight (kg) ÷ Height (m)²

Square the height measured in metres, then divide the weight in kilograms by that number. BMI alone does not determine a person's overall health.

Calculate BMI →
04

Age Calculation Method

Age = Completed years between two dates

Compare the date of birth with the reference date. If the birthday has not yet occurred in that year, subtract one from the year difference. Months and days require an additional date comparison.

Calculate Age →
COMMON QUESTIONS

Frequently Asked Questions

Find answers to common questions about everyday calculations and online calculators.

How do I calculate a percentage?

Divide the part by the total and multiply the result by 100. For example, 20 out of 80 is (20 ÷ 80) × 100 = 25%.

How is GST calculated on a product?

When GST is added to a pre-tax price, multiply the price by the applicable GST rate and divide by 100. Add that tax amount to the original price to get the total. If the displayed price already includes GST, a different calculation is needed.

What is the difference between adding and removing GST?

Adding GST calculates tax on a price before tax. Removing GST estimates the pre-tax value from a GST-inclusive price. For example, at an assumed 18% rate, a total of ₹1,180 includes a pre-tax value of ₹1,000 and GST of ₹180.

How do I calculate my BMI?

Divide your weight in kilograms by your height in metres multiplied by itself. BMI is a screening tool and should not be treated as a medical diagnosis.

Can I calculate my exact age online?

An age calculator can calculate completed years, months and days when the correct date of birth and reference date are entered. Check the dates carefully, especially around leap years.

Are online calculator results always correct?

Results depend on the formula, inputs and assumptions used. Check the entered values and independently verify results before making important financial, tax or health decisions.

Do I need to understand the formula to use a calculator?

No. You can enter the required values and use the calculator. Understanding the formula can help you interpret the result and identify input mistakes.

Where can I learn more about these calculations?

Explore the calculator pages and related educational articles on Singh Habitat for additional explanations and worked examples.

Latest Articles & Calculator Guides

Read useful guides, learn calculation methods and discover practical tips for everyday tasks.

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