如果你在ios6 +中使用自动布局，你可以通过在UILabel的子类中调整intrinsicContentSize来实现。

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        self.textAlignment = NSTextAlignmentRight;
    }
    return self;
}

- (CGSize)intrinsicContentSize 
{
    CGSize size = [super intrinsicContentSize];
    return CGSizeMake(size.width + 10.0, size.height);
}

可以使用https://github.com/mattt/TTTAttributedLabel代替UILabel

BITAttributedLabel *label = [BITAttributedLabel new];
label.font = font;
label.text = @"hello";
label.textInsets = UIEdgeInsetsMake(10, 10, 10, 10);
[label sizeToFit];

在Swift中，它是这样解决的。

class Label: UILabel {
    override func drawTextInRect(rect: CGRect) {
        super.drawTextInRect(UIEdgeInsetsInsetRect(rect, UIEdgeInsets(top: 0, left: 10, bottom: 0, right: 10)))
    }
}

如果以编程方式创建标签，则可以使用sizeThatFits方法计算填充。如果使用多行，文本将以最大宽度值换行。

let text = UILabel()
let padding = 10
text.layer.cornerRadius = 5
text.layer.masksToBounds = true
text.text = "Hello"
text.font = UIFont(name: text.font.fontName, size: 18)
text.textAlignment = NSTextAlignment.center
text.numberOfLines = 1

let maxSize = CGSize(width: 100, height: 100)
var size = text.sizeThatFits(maxSize)
size.width = size.width + padding * 2
size.height = size.height + padding * 2
text.frame = CGRect(origin: CGPoint(x: 0, y: 0), size: size)

Swift 4版的blyabtroi解决方案

let leadingMargin: CGFloat = 10
let trailingMargin: CGFloat = 10

let style = NSMutableParagraphStyle()
style.alignment = .justified
style.firstLineHeadIndent = leadingMargin
style.headIndent = leadingMargin
style.tailIndent = trailingMargin

label.attributedText = NSAttributedString(string: "Label with margins", 
                                          attributes: [NSAttributedStringKey.paragraphStyle: style])

#import "E_LabelWithPadding.h"
#define padding UIEdgeInsetsMake(2, 0, 2, 0)
#define padding1 UIEdgeInsetsMake(0, 0, 0, 0)
@implementation E_LabelWithPadding
- (void)drawTextInRect:(CGRect)rect {
if (![self.text isEqualToString:@""]) {
    [super drawTextInRect:UIEdgeInsetsInsetRect(rect, padding)];
}else {
    [super drawTextInRect:UIEdgeInsetsInsetRect(rect, padding1)];
}

}

- (CGSize) intrinsicContentSize {
if (![self.text isEqualToString:@""]) {
    CGSize superContentSize = [super intrinsicContentSize];
    CGFloat width = superContentSize.width + padding.left + padding.right;
    CGFloat height = superContentSize.height + padding.top + padding.bottom;
    return CGSizeMake(width, height);
}else {
    CGSize superContentSize = [super intrinsicContentSize];
    CGFloat width = superContentSize.width + padding1.left + padding1.right;
    CGFloat height = superContentSize.height + padding1.top + padding1.bottom;
    return CGSizeMake(width, height);
}

}

- (CGSize) sizeThatFits:(CGSize)size {
if (![self.text isEqualToString:@""]) {
    CGSize superSizeThatFits = [super sizeThatFits:size];
    CGFloat width = superSizeThatFits.width + padding.left + padding.right;
    CGFloat height = superSizeThatFits.height + padding.top + padding.bottom;
    return CGSizeMake(width, height);
}else {
    CGSize superSizeThatFits = [super sizeThatFits:size];
    CGFloat width = superSizeThatFits.width + padding1.left + padding1.right;
    CGFloat height = superSizeThatFits.height + padding1.top + padding1.bottom;
    return CGSizeMake(width, height);
}

}

@end