Excel Challenge 21 : Calculate BMI (Index)

The Problem

Health trackers usually store weight and height as separate numbers, which works fine until someone wants a BMI view from the same sheet. Once the list gets longer, the calculation has to stay consistent from row to row, because one small formula mistake can push a result into the wrong health label.

The tricky part is that BMI is not just a simple divide-and-forget formula. Height has to be squared first, then the score still needs to become a readable category so the summary tells a clearer story than a pile of decimals. The flow below shows that path from raw measurements into a score and then into a label.

The Problem: BMI From Raw Measurements The sheet needs to turn weight and height into a score, then turn that score into a clear category.

That is the situation behind this workbook. The raw values are already there, but the sheet still needs to do the calculation in a way that stays readable for anyone checking the file later.

Weight and height are already stored for each participant.
The BMI result must be calculated row by row.
The score needs a simple health label after that.
The summary section should count records and healthy results.

In practice, the sheet needs to keep the math stable, the category labels readable, and the summary easy to trust. A result like 23.03 is useful, but the workbook becomes much easier to review once that number is paired with a category like Healthy.

How We Solve It

The BMI formula is weight divided by height squared. In Excel, that means using either the exponent operator ^ or the POWER function to square height before dividing.

Once the BMI is calculated, IFS can assign a readable label based on threshold ranges. That makes the sheet much easier to review than a plain list of decimal results.

Method 1: Use the Exponent Operator

Method 1: Use the exponent operator to square height before dividing weight by it.

This is the shortest version of the BMI formula. Height is squared with ^2, then weight is divided by that result.

The key detail is the parentheses. They make sure the squaring happens in the denominator before the division uses the result.

=B2/(C2^2)

Method 2: Use POWER for Readability

Method 2: Use POWER when you want the same math written more explicitly.

POWER does the same math as ^, but some people prefer it because the intent is easier to read at a glance.

That can help when the workbook is shared with someone who understands functions more quickly than operators.

=B2/POWER(C2,2)

Method 3: Convert BMI to a Category

Method 3: Turn the BMI score into a readable category with IFS.

Raw BMI values are useful, but the category is easier to scan. IFS lets you test the BMI against multiple ranges in order and return the right label.

This makes the sheet easier to review quickly, especially when the goal is to count how many people fall into a specific range.

=IFS(D2<18.5,"Underweight",D2<25,"Healthy",D2<30,"Overweight",TRUE,"Obese")

Function Explanation

1. Division and Exponentiation

The main calculation is weight divided by height squared. That means Excel needs both division and exponent logic in the same formula.

The important part is the structure, not just the symbols. If the denominator is written incorrectly, the BMI result will also be wrong.

2. POWER

POWER raises a number to a chosen exponent. In this challenge, it is simply another way to square height.

It is useful when you want the formula to read more like a named step instead of a math operator.

Learn more this functionPOWER

3. IFS

IFS tests several conditions in order and returns the first matching result. That makes it a good fit for category bands like BMI ranges.

Instead of writing nested IF formulas, you can read the ranges from top to bottom and see the category logic more clearly.

Learn more this functionIFS

If you ever get strange BMI results, check the height unit first. The challenge uses meters, so the formula assumes the values in column C are already in meters.