How to calculate the percentages on the Xiaomi calculator: from simple calculations to hidden chips

Introduction: Why can you count percentages on a smartphone?

Xiaomi’s modern smartphones are replacing many devices, from the camera to the banking terminal. But one of the most popular features goes unnoticed: a built-in calculator with support for percentage calculations. The ability to quickly calculate interest on the go will come in handy in the store (to calculate discounts), when analyzing credit rates or even calculating tips in a cafe. However, many users still do not know how to use this feature effectively – especially on the Mi Calculator.

In this article, we will not only look at the basic operations (how to add or subtract percentages), but also the hidden capabilities of the Xiaomi calculator that are not on the surface. For example, did you know that you can calculate percentages of interest or use the calculator memory for complex chains of calculations? and also find out why sometimes the results in standard and engineering modes differ – and how to avoid this.

If you think interest is boring, we'll have to dissuade you.

• 📉 Instantly calculate discounts in stores without the help of sellers
• 💰 Check the correctness of interest on loans or deposits
• 📊 Analyze the dynamics of changes (for example, the rise or fall of the exchange rate)
• 🧮 Use an engineering calculator for complex financial calculations

Where to find a calculator on Xiaomi and how to open it

Before we get to the calculations, we need to make sure that you are using the standard Mi Calculator app, not a third-party calculator, and the fact is that the algorithms of the calculations may differ, and in this article we focus on the company’s solution from Xiaomi.

To open the calculator:

1. Swipe up the screen to open the app menu.
2. Find the icon "Calculator"** (usually it has the form of a gray square with numbers).
3. Click on it and the standard mode will open.

If the icon is not on the home screen, check the Tools folder or search the system (swipe down the screen and type “calculator” in the search bar).

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On some Xiaomi models (e.g. Redmi Note 12 or X-ray) POCO X5) The calculator can be hidden in the Google folder.If you don't find it, try installing the official Mi Calculator app from Google Play.

After opening, you will see two modes:

• 🔧 Engineering – for complex operations (trigonometry, logarithms, power functions).

To switch between modes, click on three horizontal lines in the upper left corner (☰) And you can choose the right option. MIUI 14+ The engineering mode can be hidden - it must be activated in the calculator settings.

Basic Interest Transactions: Adding and Subtracting

So, to start with, the simplest thing is how to add or subtract percentages, which is the most common operation that you can use to calculate discounts, taxes, or allowances.

How to add interest to the number

Let's say you want to know what 20 percent of the 5,000 rubles is and add that value to the original sum.

1. Enter the reference number: 5,000.
2. Press the button. × (multiply).
3. Enter percentage: 20.
4. Press the % button.
5. Now press. + and enter the original number again: 5,000.
6. Press. = — result: 6,000.

Faster way (for example, for MIUI 13+):

5000 + 20% = 6000

Just enter a number, then a sign. +, percentage and press =. The calculator will automatically calculate the percentage of the first number and add it.

How to subtract interest from the number

Similarly, subtraction works, for example, to find out the amount after a 15% discount from 3000 rubles:

3000 − 15% = 2550

Or Step-by-step:

1. 3000 × 15% → get 450 (discount).
2. 3000 − 450 = 2550.

Make sure you enter the initial amount without errors.|

Use the % sign only after entering the percentage value|

For complex discounts (for example, 10% + 5%) count them consistently|

Compare the result with an online calculator to check-->

Please note: if you enter 3000 × 15 If you press % after multiplying, the result will be wrong, the right order: first percentage, then multiplication or division.

⚠️ Note: Some Xiaomi models (e.g. Redmi) 9A) The % button works differently, it divides the last number by 100. To avoid errors, always check the logic of the calculation with a simple example (for example, the following example, 100 + 10% should 110, not 100.1).

Complex interest calculations: interest rates, chain of operations

Now, to more complex scenarios, where interest is calculated not from the original number, but from the result of the previous transaction, which can be useful for analyzing multi-year deposits, complex rebates or tax charges.

Interest on interest (consecutive accrual)

Imagine that you put money on a deposit at 10% per annum, and after a year the bank increases the rate to 12%. How to calculate the total amount in 2 years, if the initial deposit is 10,000 rubles?

Algorithm:

1. First year: 10000 × 10% = 1000 (Revenue: 10000 + 1000 = 11000.
2. Second year: 11000 × 12% = 1320 (Revenue: 11000 + 1320 = 12320.

On the Xiaomi calculator, this can be done in one chain:

10000 × 1.1 × 1.12 = 12320

Where 1.1 is 100% + 10%, and 1.12 is 100% + 12%.

Using calculator memory for complex calculations

If you need to calculate the percentages of the intermediate result (for example, a discount on an already discounted product), it is convenient to use the calculator memory (M).+, M-, MR).

Example: the goods cost 5000 rubles, it is a 20% discount, and then another 10% on the amount received.

1. Count the first discount: 5000 × 20% = 1000 → 5000 − 1000 = 4000.
2. Save the intermediate result: press 4000, then M+.
3. Count the second discount: 4000 × 10% = 400 → 4000 − 400 = 3600.
4. Check the result in memory: MR (It should be 4,000).

Every day.|

Several times a week |

Rarely, only in the store.|

I've never used that function.-->

Engineering Calculator: Hidden Functions for Interests

If the standard mode is limited to basic operations, the Mi Calculator provides access to advanced features, where you can calculate percentages in complex formulas, use variables, and even plot (on some models).

How to turn on the engineering mode

If you do not have an engineering calculator:

1. Open the standard calculator.
2. Press three lines (☰) top-left.
3. Choose Engineering.
4. If there is no item, go to Settings. → Additionally. → Show an engineering calculator.

In engineering mode, the % button works differently, converting a number to a decimal fraction (e.g., 15% becomes 0.15) which is convenient for formulas, but can be confusing for beginners.

Examples of calculations in engineering mode

Task 1: Calculate what 7% of 1200 is and then add that value to another number (500).

1200 × 7% + 500 = 500 + (1200 × 0.07) = 584

Task 2: Find out how much 1500 percent is more than 1,200 percent.

(1500 − 1200) ÷ 1200 × 100% = 25%

In engineering mode, you can use brackets for complex expressions, such as:

(2000 × (1 + 10%)) ÷ (1 + 5%) − 1000 = 1047.62

⚠️ Attention: POCO F3 In some other models, the % button works as ÷100. This means that 50 percent will be interpreted as 0.5, not as an operation on a number. × (percentage ÷ 100).

Common Mistakes When Calculating Interest on Xiaomi

Even in simple operations, users often make mistakes that lead to incorrect results, and let's take the most common ones and learn to avoid them.

Mistake 1: Wrong order of operations

The calculator does the first thing, multiplication/division, then addition/subtraction.

1000 + 20% × 500

Then it'll be counted first. 20% × 500 = 100, then 1000 + 100 = 1100. But if you need to add more 20% ce 1000, and then multiply by 500, use brackets:

(1000 + 20%) × 500 = 600000

Mistake 2: Confusion between “percentage of” and “percentage change”

Many people confuse:

• 🔢 Percentage of number (e.g, 10% from 200 = 20).
• 🔄 Percentage change (e.g., “by how much per cent 250 is greater than 200?» → 25%).

For the second case, use the formula:

(new value − old value) ÷ old value × 100%

Mistake 3: Ignoring rounding

Xiaomi's default calculator is 10 decimal places, but real-world calculations (e.g. financial) often require rounding.

1. Go to Engineering Mode.
2. Press. 2nd (Shift on some models).
3. Select Fix and specify the number of characters (e.g. 2 for kopecks).

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Always check the rounding setting before making financial calculations! For example, when calculating interest on a loan, a difference of 0.01% can lead to an error of hundreds of rubles on large amounts.

Practical examples: where interest on a smartphone will come in handy

Theory is good, but let’s take a look at real-world situations where being able to quickly calculate interest on Xiaomi will save you time and money.

Example 1: Calculation of discounts in the store

You see a 3,499 ruble item at 30% off. How much will it cost?

3499 − 30% = 2449.3

But the price is listed at the store as 2499 rubles, which means that the discount is actually:

(3499 − 2499) ÷ 3499 × 100% ≈ 28.6%

The seller has slightly overstated the original price.

Example 2: Checking the loan offer

The bank offers a loan of 50,000 rubles at 12% per annum. How much will you overpay in a year?

50000 × 12% = 6000

But if the loan is for 2 years with a monthly accrual of interest, the formula becomes more complicated:

50000 × (1 + 12% ÷ 12)^24 ≈ 63 528

The overpayment will be 13 528 rubles (not 12 000, as it might seem).

Example 3: Analysis of currency growth/fall

Let's say the dollar went from 75 rubles to 82 rubles. How much did it change by?

(82 − 75) ÷ 75 × 100% ≈ 9.33%

And if you need to know how many rubles it will take to buy $ 100 after the rate rises:

100 × 82 = 8200

And how much more than before:

(8200 − 7500) ÷ 7500 × 100% ≈ 9.33%

Comparison with other calculators: what is Xiaomi better (or worse)

Not all calculators are equally useful. Let's compare the capabilities of the Mi Calculator with alternatives to understand when to use third-party apps.

As you can see from the table, the Mi Calculator is one of the most functional built-in calculators, but for specialized tasks (such as mortgage or tax calculations), you may need third-party solutions like the Calculator.++ Financial Calculator.

Advantages of Mi Calculator:

• 🔹 Full integration with MIUI (quick access from the notification curtain).
• 🔹 Support for both simple and engineering calculations.
• 🔹 No advertising and unnecessary permissions (unlike many third-party apps).

Disadvantages:

• 🔸 No templates for loans/deposits.
• 🔸 Some models (Redmi 10) have no computational history.

FAQ: Frequent questions about percentages on Xiaomi calculator