Padding.swift

class PaddingLabel: UILabel {
    
    var topInset: CGFloat
    var bottomInset: CGFloat
    var leftInset: CGFloat
    var rightInset: CGFloat
    
    required init(withInsets top: CGFloat, _ bottom: CGFloat, _ left: CGFloat, _ right: CGFloat) {
        self.topInset = top
        self.bottomInset = bottom
        self.leftInset = left
        self.rightInset = right
        super.init(frame: CGRect.zero)
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func drawText(in rect: CGRect) {
        let insets = UIEdgeInsets(top: topInset, left: leftInset, bottom: bottomInset, right: rightInset)
        super.drawText(in: rect.inset(by: insets))
    }
    
    override var intrinsicContentSize: CGSize {
        get {
            var contentSize = super.intrinsicContentSize
            contentSize.height += topInset + bottomInset
            contentSize.width += leftInset + rightInset
            return contentSize
        }
    }
    
}


// Usage
import UIKit

class ViewController: UIViewController {

    public static var label: UILabel = {
        let label = PaddingLabel(withInsets: 8, 8, 18, 18)
        label.text = "Some text"
        label.textColor = .white
        label.textAlignment = .center
        label.font = UIFont.systemFont(ofSize: 26, weight: UIFont.Weight.regular)
        label.layer.backgroundColor = UIColor.black.withAlphaComponent(0.14).cgColor
        label.layer.cornerRadius = 24
        return label
    }()

}



// Version 2 12.04.2020
class PaddingLabel: UILabel {
    
    var insets = UIEdgeInsets.zero
    
    /// Добавляет отступы 
    func padding(_ top: CGFloat, _ bottom: CGFloat, _ left: CGFloat, _ right: CGFloat) {
        self.frame = CGRect(x: 0, y: 0, width: self.frame.width + left + right, height: self.frame.height + top + bottom)
        insets = UIEdgeInsets(top: top, left: left, bottom: bottom, right: right)
    }
    
    override func drawText(in rect: CGRect) {
        super.drawText(in: rect.inset(by: insets))
    }
    
    override var intrinsicContentSize: CGSize {
        get {
            var contentSize = super.intrinsicContentSize
            contentSize.height += insets.top + insets.bottom
            contentSize.width += insets.left + insets.right
            return contentSize
        }
    }
}

// Применение
class ViewController: UIViewController {

    @IBOutlet weak var label: PaddingLabel!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        label.text = "Какой-то текст"
        label.textColor = UIColor.white
        label.padding(2, 2, 5, 5)
        label.layer.cornerRadius = 5.0
        label.layer.backgroundColor = UIColor.red
    }

}