Rocket.Chat/apps/meteor/client/lib/utils/formatBytes.ts

export const formatBytes = (bytes: number, decimals?: number): string => {
	if (bytes === 0) {
		return '0 Bytes';
	}

	const k = 1024;
	const dm = decimals || 0;

	const sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB', 'PB'];

	const i = Math.floor(Math.log(bytes) / Math.log(k));

	return `${parseFloat((bytes / Math.pow(k, i)).toFixed(dm))} ${sizes[i]}`;
};