Font size unit conversion

1Pixel = 0.75Point

0.75

Typography Units

Point (pt)0.75

Pixel (px)1

Density-independent Pixel (dp)0.75

Scale-independent Pixel (sp)0.75

Free online font size unit conversion tool that supports two-way real-time conversion of 4 commonly used typesetting/UI units: pt, px, dp, and sp. The current page adopts a fixed reference relationship: 1 px = 0.75 pt, 1 pt ≈ 1.333 px. At the same time, in this tool, dp and sp are mapped to pt according to the same reference basis, which facilitates quick static comparison between design drafts, Web/CSS descriptions and Android UI annotations. It should be noted that this page does not read browser scaling, device pixel density, Android font scaling or real print size, so it is more suitable for specification comparison and document unification rather than replacing real device rendering testing. All calculations are done locally in the browser, and the data is not uploaded to the server.

Length Converter

When you need real physical lengths such as mm, cm, and in, you should switch to length unit processing

Area Converter

When estimating page canvas, paper area or printing layout, you often need to continue processing area caliber

Unit Converter

You can switch directly when you need to continue processing length or other supporting units

About the static conversion caliber of pt, px, dp, sp

pt (point) is a common font size unit in the classic typesetting context. Many document editors, presentation software, brand manuals and font specifications like to use pt to express text size. px (pixel) is more commonly used in web pages, design drafts and CSS annotations. It emphasizes the reference size in the context of screen and interface.

It is important to note that px in CSS is not always equal to a physical pixel on the device, it is closer to the "reference pixel". Therefore, the 16 px on the design drawing, the 16 px in the web page style, and the final visual size displayed on the mobile screen will still be affected by scaling, density, and platform implementation.

dp and sp are more common in the Android interface context. Generally speaking, dp is more biased towards interface layout size, while sp is more biased towards font size and will consider system font scaling. However, this page is not a runtime simulator. It will not read the density or font scaling of a certain mobile phone. It just puts these units on a unified reference ruler for static comparison.

This page currently uses a fixed reference relationship: 1 px = 0.75 pt, 1 pt ≈ 1.333 px, and maps dp and sp to the same reference datum, which facilitates rapid unification of design drafts, specification documents, and cross-end communication. It solves the problem of "how to compare and write documents", not the problem of "how large the final display size must be on the device".

If your work goal is real printing size, paper millimeter accuracy, browser rem/em system or Android real machine font scaling verification, then you should use the corresponding length tools, design software or real device testing instead. This page is better suited for specification drafting, early review, and delivery documentation.

Use Cases

Quickly change the 16 px, 18 px, and 24 px font sizes in the design draft to pt to facilitate writing into PPT, Word or brand specification documents
Change the 12 pt, 14 pt, and 18 pt font sizes given in the document to px to facilitate comparison between the front-end and the designer
When delivering web design, put CSS Unify common font sizes with the pt caliber in presentation documents
In the Android UI description, quickly replace pt or px in the design draft with dp and sp reference values to facilitate communication
When organizing the text specifications of the component library, unify the font size unit writing of buttons, text, titles, and subtitles
Mix the px and pt used in historical design systems Unify font sizes into the same set of comparison tables to reduce migration costs
Add dual-unit annotations to cross-team collaboration documents, so that design, front-end and mobile terminals can quickly understand the same font size
When doing visual inspection and QA, quickly convert and compare different units in design draft annotations and code styles
When preparing brand manuals, event posters or presentation templates, first unify font size rules into a reference size before distributing
Prepare a unified font size comparison table for emails, landing pages, H5 and app copywriting interfaces
In education and training or internal sharing, explain the differences and common conversion relationships of pt, px, dp, sp
Quickly convert the font size annotation on the screenshot into another set of units that are more familiar to the team to facilitate review and modification
When doing multi-language product documentation, use unified conversion caliber to supplement font size examples for different platforms
In the early review stage when there is no equipment to test, first use static conversion to quickly determine whether the font size level is generally reasonable

How to Use

Fill in the known font size value in the input box, supporting integers and decimals.
Select the source unit on the left, optional pt, px, dp, sp.
Select the target unit on the right, and the results will be updated immediately; you can click the middle swap button when you need to view it in reverse.
If you want to see it all at once, expand the results panel to view the complete correspondence of the value in 4 units at the same time.

Features

4 high-frequency font sizes/UI units covering: pt, px, dp, sp, suitable for quick comparison during design, front-end and mobile delivery
Two-way instant conversion: the result is updated immediately after entering the value, the source unit and target unit can be freely switched without clicking the conversion button
Fixed reference relationship transparency: the current page uses 1 px = 0.75 pt, 1 pt ≈ The common benchmark of 1.333 px facilitates the unified caliber of specifications and design drafts
Clear static comparison of dp and sp: This page puts dp and sp on the same reference ruler for quick conversion, suitable for writing documents, making annotations and cross-team communication
Can be expanded to view all results: the same font size value is in pt, px, dp, sp The corresponding values below can be displayed at the same time to facilitate one-time checking
Suitable for small numbers and intermediate values: common non-integer values in designs such as 13.5 px, 10.5 pt, 14 sp can also be directly converted
Clearly prompt the rendering boundary: the page will distinguish "static conversion" and "real device display" to reduce the risk of mistaking the reference value for the final physical size
Pure browser local calculation: no network requests, no server logs, your design annotations, component specifications and delivery document parameters will not leave the device

How to choose the font size unit?

It is also about writing "how big is the font size", and different units are suitable for different scenarios. First figure out whether you are writing a design draft, a web style, or an Android specification.

Unit	The most common scenarios	Advantages	Notes	This page supports
pt	Word, PPT, PDF, brand specifications, font documents	Most common in typesetting and document contexts, easy to align with font instructions	When switching to screen context, it is best to add a column of px comparison	Supported
px	Web pages, design drafts, CSS annotations, interface drafts	The communication between design and front-end is the most direct, and the most common in implementation	Not absolute physical pixels, browsers and devices will affect the final display	Support
dp	Android layout and interface annotation	Suitable for cross-density device description logical size	This page does not simulate real device density, only static reference conversion	Support
sp	Android text size annotation	Suitable for text context and easy to communicate with mobile teams	Real display will also be affected by system font scaling	Support
em / rem / mm / in	Web relative units or physical printing size	Suitable for specific design and implementation systems	It is not within the support range of the current page, and other tools or benchmarks need to be used	Not supported

Best Practices

First agree on a unified benchmark for the team, and then compare it across units

If the design, front-end, and mobile terminals do not clearly explain the conversion benchmark first, it is easy for the same 16 to be understood as different visual sizes. It will be more stable to unify the caliber first, and then use this page to supplement the double unit labeling.

Treat the results of this page as a delivery reference value, not the final rendering result

This page is suitable for static comparison of design drafts, documents and specifications, but browser scaling, device density and system font settings may make the actual display slightly different. Visual verification should still be done in the target environment before going online.

Switch to length units and real typesetting software when physical dimensions are required

If your goal is to confirm the actual paper size, the millimeter accuracy of the printed product, or the physical size of the exported PDF, then don't just look at the static conversion results of pt/px/dp/sp.

Android text takes into account system font scaling

sp Performance on real devices will be affected by system font scaling. This page can only give you static reference values. When it comes to accessibility and multi-device adaptation, you must test it on a real device.

Web If you actually use rem or em, first clarify the root font size

This page does not directly change rem/em, but you can still restore rem/em to px according to the project root font size, and then compare it with pt or design annotations. The key is to get the context clear first.

Try to retain both the original unit and the conversion result when delivering.

For example, writing it as 16 px / 12 pt or 14 sp / 14 pt will allow the recipient to quickly understand your original intention and facilitate subsequent traceback.

FAQ

What units does this font size unit converter support?

This page currently supports 4 units: pt, px, dp, sp. It is suitable for static numerical comparison in design drafts, CSS font sizes, Android UI annotations and component documents. The current page does not support other typesetting/length units such as em, rem, mm, cm, in or pc.

1 pt is equal to how many px? 16 px is equal to how many pt?

According to the fixed reference relationship currently adopted on this page, 1 pt ≈ 1.333 px, 1 px = 0.75 pt. So 16 px = 12 pt, 12 pt = 16 px, 18 px = 13.5 pt. This caliber is very suitable for quick cross-checking between web design drafts and presentation documents.

What is the difference between px and pt?

pt (point) is more focused on typesetting and document context, and historically often appears together with printing and font size; px (pixel) is more focused on screen and CSS context, and is commonly used in web pages and design draft annotations. They can both be used to describe font sizes, but the usage environments are different, so many teams will need to do conversion comparisons between px and pt when delivering designs.

What is the difference between dp and sp?

dp is usually used for interface size expression in Android that is related to density but does not follow font scaling, and sp is usually used for text size expression that will follow font scaling. It should be noted that for the purpose of static specification comparison, this page does not read the real device density or system font scaling, but puts them on a unified reference basis for linear conversion.

Why may the value swapped out from the page not be exactly the same as the real device display?

Because the real display effect will be affected by browser scaling, device pixel density, root font size, system font scaling, platform rendering strategy and design software export rules. The goal of this page is to unify static calibers, not to simulate the rendering results of real devices. So before finally going live, you should still do an actual visual inspection on the target browser or target device.

Why are the relationships between dp, sp and pt in this tool so close?

Because the current page uses static conversion calibers under a unified reference ruler, which allows you to quickly compare different units in documents, design drafts and specifications, instead of reading the real-time rendering environment of a certain device. You can think of this as a "conversion reference value as delivered", rather than a real pixel calculator in the Android runtime.

Can it be exchanged for rem, em, mm, cm or inches?

Not currently. The actual supported range of this page is only four units: pt, px, dp, and sp. If you need relative units such as rem and em, or physical length units such as mm, cm, and in, you should use the corresponding design basis or other length tools to handle them separately.

Is this page suitable for real printing or printing size calculation?

It is not suitable for direct replacement of real printing size calculation. Because this page currently does not provide physical length units such as mm, cm, and in, nor does it handle printer DPI, output media, and document layout rules. If you want to confirm the actual paper size, you should use length units and actual typesetting software for final verification instead.

Can I enter a decimal value like 13.5 px?

Yes. Non-integer values such as 10.5 pt, 13.5 px, and 14 sp are commonly used in design systems and interface fine-tuning scenarios. This page can directly convert them. This will make it more convenient when delivering component specifications, organizing annotation documents, and doing multi-end comparisons.

How should I use this tool when delivering designs?

A safer approach is to retain the original design units and then use this page to fill in a column of converted reference values. For example, if the design draft is written at 16 px, you can also write it at 16 px / 12 pt for the front-end or documentation team. As long as the team agrees on the same conversion basis first, the communication cost will be much lower.

Can this page be used offline? Will the data be uploaded?

Yes. After the page is loaded, all font size conversions are performed locally in the browser, with no network requests, no server logs, and no form submissions. Your design specifications, component annotations and delivery document parameters will not be uploaded to the server, and the input will be cleared after closing the page.

Glossary

Point (pt): Classic typesetting font size unit, commonly used in Word, PPT, PDF, brand specifications and font description documents.
Pixel (px): One of the most common interface units in web pages and design drafts, in CSS it is closer to a reference pixel than to an absolute physical pixel.
Density-independent pixel (dp): A common logical size unit in the Android context, used to maintain relatively consistent interface scale across devices of different densities.
Font scaling pixel (sp): A common unit in Android text context, usually considering system font scaling, suitable for expressing text size.
CSS reference pixel: The reference length concept used in browser layout is not necessarily equal to a physical pixel on the screen.
Device pixel density: How many physical pixels there are per unit length of the screen will affect the actual display effect of the same logical unit on different devices.
Font scaling: Additional scaling settings for text size at the operating system or application level will affect the actual display results.
Fixed reference conversion: Does static linear conversion under a unified benchmark, which is suitable for comparison between documents and design delivery, but it is not equivalent to real device rendering simulation.

Quick check on common font size conversion anchor points

These comparison values are most commonly used in design drafts, CSS, and document delivery.

pt	px	dp (caliber of this page)	sp (caliber of this page)	Typical scenario
9pt	12px	9dp	9sp	Minimal auxiliary information, table secondary description
10.5pt	14px	10.5dp	10.5sp	Small text, description text
12pt	16px	12dp	12sp	Common body or form text
13.5pt	18px	13.5dp	13.5sp	Emphasis on text and card titles
18pt	24 px	18dp	18sp	Big title or page key information
24pt	32 px	24dp	24sp	Cover title, Hero title

Select font size unit according to scene

The same font size value is written in different units and serves different collaboration objects.

Scenario	More suitable unit	Reason
PPT, Word, brand manual, PDF specification	pt	The most natural in the document and typesetting context, and the easiest to align with the font specification
Web page style, design draft, Figma/CSS delivery	px	The lowest cost of communication between design and front-end implementation
Android layout size description	dp	Closer to Android logical size context
Android text size description	sp	Closer to the context of mobile font annotation, but ultimately still depends on real machine scaling
Delivery documents across teams	Retain the original units and add a column of conversion values	Can take into account the reading habits of design, front-end and mobile terminals

Privacy & Security

All font size conversions on this page are completed in your browser. The design annotations, font specifications, component documents, and delivery parameters you enter never leave your device—no network requests, no server logs, and your entries are cleared when you close the page. For internal design systems and unpublished specifications, this page does not capture or store any content.