CSS calc() Function

Assurance Uwangue

Introduction

CSS has a special calc() function for doing basic math. The calc() function lets you perform calculations when specifying CSS property values. In this article, we will cover just about everything there is to know about this useful function.

Understanding the CSS calc() Function

Syntax

It can be used wherever length values are accepted in CSS properties. It can be used with numbers or integers, length, frequency, angle, time, and percentage values.

Example of calc() function

In this example, the calc() function takes a single expression as its parameter, and the expression’s result is used as the value for a CSS property. 



Within the Calc() function the operands can be combined using the supported operator listed below.

Supported Operators

Addition (+) // Adds the specified operands.
Subtraction (-) // Subtracts the second operand from the first operand.
Multiplication (*) // Multiplies the specified operands.
Division (/) // Divides the left-side operand (dividend) by the right-side operand (divisor).

Units

calc() can operate with different units, such as px %, em, rem, in, mm, cm, pt, pc, ex, ch, vh, vw, vmin, vmax. It can even mix or combine different units of measure within a single expression.

Browser Support

It’s important to note that while calc() is widely supported, there might be some older versions of browsers or specific browser configurations that do not support it. However, for most practical purposes and when targeting modern browsers, you can rely on widespread support for calc() in CSS. 



Always consider providing fallbacks or alternatives for browsers that do not support specific CSS features if necessary.

Key points to note about its usage

  1. The + and - operators should always be surrounded by whitespace. For instance, calc(20% -6px) it will be parsed as “a percentage followed by a negative length” — which is an invalid expression — while calc(20% - 6px) is “a percentage followed by a subtraction operator and a length”. Likewise, calc(6px + -20%) is treated as “a length followed by an addition operator and a negative percentage”.
  2. While whitespace is not mandatory for the * and / operators, it’s advisable to include it for consistency.
  3. Nesting calc() functions are allowed; in such cases, the inner functions are interpreted as regular parentheses.
  4. For lengths, you can’t use 0 to mean 0px (or another length unit); instead, you must use the version with the unit: margin-top: calc(0px + 10px); is valid, while margin-top: calc(0 + 10px); is invalid.
  5. The calc() function cannot directly substitute the numeric value for percentage types; for instance calc(100 / 4)% is invalid, while calc(100% / 4) is valid.
  6. The calc() isn’t supported when applied to media queries.
  7. You can’t combine calc() and attr()

Practical Uses of calc() Function

Responsive Design

  1. Calc() is commonly used in responsive web design to create flexible layouts that adapt to different screen sizes.
  2. It allows for dynamic adjustments based on viewport dimensions.

Spacing and Sizing

  1. Calc() can calculate margins, paddings, and sizes based on various factors, providing more precise control over layout spacing.

Grid Systems & Aspect Ratios

  1. When building grid systems, calc() can help distribute space evenly among grid items while considering gutters and margins.
  2. It’s useful for maintaining aspect ratios of elements, especially when combining percentages and fixed values.

Dynamic Styling

  1. When building grid systems, calc() can help distribute space evenly among grid items while considering gutters and margins.
  2. It’s useful for maintaining aspect ratios of elements, especially when combining percentages and fixed values.

Automatically sizing elements to fit their container

  1. Ensures the form fields fit in the available space, without extruding past the edge of its container while maintaining an appropriate margin.

In this case the form field is one-sixth the width of the window. Then, we use calc() to make sure the input fields are a good size by subtracting 1em from its container’s width.

Summary

  • The calc() function in CSS is a powerful tool that allows for dynamic calculations within CSS property values.
  • Its flexibility makes it invaluable for responsive design, spacing and sizing, grid systems, aspect ratios, and dynamic styling.
  • Understanding how to use calc() effectively can significantly enhance the layout and responsiveness of web pages.
  • Browser support is very good for calc(). It works in all modern browsers including Chrome, Firefox, Safari, and Edge.

Reference

https://developer.mozilla.org/en-US/docs/Web/CSS/calc
https://css-tricks.com/a-complete-guide-to-calc-in-css/
https://www.w3schools.com/cssref/func_calc.php