如何在React Native中设置pt单位的字体大小？

Hey there! Let's break down your questions about React Native font units clearly and directly:

1. What's the default font size unit in React Native? #

React Native uses logical pixels as its default unit for font sizes—this translates directly to pt on iOS and dp on Android. When you write fontSize: 16 in your styles, you're not setting CSS-style pixels; you're using a platform-adapted unit that ensures consistent physical sizing across devices. So to put it simply: RN's "unitless" fontSize values are effectively pt on iOS.

2. How to set font sizes using pt? #

Great news—you don't need any extra work to use pt in React Native! On iOS, the fontSize property natively uses pt as its unit. For example, fontSize: 12 will render exactly as 12pt on iOS, and Android will automatically convert that value to the equivalent dp (which matches pt for consistent visual sizing across platforms).

If you ever need explicit platform-specific control (though it's rarely necessary), you can use the Platform module:

import { Platform, StyleSheet } from 'react-native';

const styles = StyleSheet.create({
  customText: {
    fontSize: Platform.OS === 'ios' ? 13 : 13, // 13pt on iOS, 13dp on Android (visually identical)
  },
});

But for most scenarios, just setting fontSize: [your desired pt value] works seamlessly across both platforms.

3. How to set a 13pt font size? #

Since React Native's fontSize maps directly to pt on iOS, you can simply write:

fontSize: 13

That's all there is to it! No need to convert from px or em—RN handles the cross-platform adaptation for you.

To clarify your conversion note: while 1em = 12pt = 16px is a common web CSS reference, React Native doesn't support em units for styling, so you can ignore that conversion here. Just use the direct pt value in your fontSize property, and it will render correctly as 13pt on iOS (with the adaptive equivalent on Android).

内容的提问来源于stack exchange，提问作者Dmitry Yakov