1let label = UILabel()
2label.translatesAutoresizingMaskIntoConstraints = false
3label.numberOfLines = 0  // Required — 0 means unlimited lines
4label.lineBreakMode = .byWordWrapping
5label.text = "This is a long text that will wrap to multiple lines and the label will automatically grow taller to fit all the content."
6label.font = .systemFont(ofSize: 16)
7
8view.addSubview(label)
9
10NSLayoutConstraint.activate([
11    label.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 20),
12    label.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 16),
13    label.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -16),
14    // Do NOT set a height constraint — let intrinsic content size handle it
15])

11. Select the UILabel in the storyboard
22. Set "Lines" to 0 in the Attributes Inspector
33. Set "Line Break" to "Word Wrap"
44. Add constraints: leading, trailing, top (or bottom)
55. Do NOT add a height constraint
66. If Xcode shows a warning about ambiguous height, set Content Hugging
7   Priority (Vertical) to 251 and Content Compression Resistance to 750

1// Calculate the height a label needs for given text and width
2func heightForText(_ text: String, font: UIFont, width: CGFloat) -> CGFloat {
3    let constraintSize = CGSize(width: width, height: .greatestFiniteMagnitude)
4    let boundingBox = text.boundingRect(
5        with: constraintSize,
6        options: [.usesLineFragmentOrigin, .usesFontLeading],
7        attributes: [.font: font],
8        context: nil
9    )
10    return ceil(boundingBox.height)
11}
12
13// Usage
14let text = "A long paragraph of text that needs to wrap across multiple lines."
15let height = heightForText(text, font: .systemFont(ofSize: 16), width: 300)
16print("Required height: \(height)")
17
18// Alternative: use sizeThatFits
19let label = UILabel()
20label.numberOfLines = 0
21label.font = .systemFont(ofSize: 16)
22label.text = text
23let size = label.sizeThatFits(CGSize(width: 300, height: .greatestFiniteMagnitude))
24print("Size: \(size)")  // CGSize(width: ~300, height: calculated)

1class DynamicCell: UITableViewCell {
2
3    private let messageLabel: UILabel = {
4        let label = UILabel()
5        label.numberOfLines = 0
6        label.font = .systemFont(ofSize: 15)
7        label.translatesAutoresizingMaskIntoConstraints = false
8        return label
9    }()
10
11    override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
12        super.init(style: style, reuseIdentifier: reuseIdentifier)
13
14        contentView.addSubview(messageLabel)
15        NSLayoutConstraint.activate([
16            messageLabel.topAnchor.constraint(equalTo: contentView.topAnchor, constant: 12),
17            messageLabel.leadingAnchor.constraint(equalTo: contentView.leadingAnchor, constant: 16),
18            messageLabel.trailingAnchor.constraint(equalTo: contentView.trailingAnchor, constant: -16),
19            messageLabel.bottomAnchor.constraint(equalTo: contentView.bottomAnchor, constant: -12),
20        ])
21    }
22
23    required init?(coder: NSCoder) { fatalError() }
24
25    func configure(with text: String) {
26        messageLabel.text = text
27    }
28}
29
30// In the UITableViewController
31override func viewDidLoad() {
32    super.viewDidLoad()
33    tableView.rowHeight = UITableView.automaticDimension
34    tableView.estimatedRowHeight = 60
35    tableView.register(DynamicCell.self, forCellReuseIdentifier: "cell")
36}

1let attributedText = NSMutableAttributedString(string: "Bold Title\n", attributes: [
2    .font: UIFont.boldSystemFont(ofSize: 18)
3])
4attributedText.append(NSAttributedString(string: "Regular body text that can be quite long.", attributes: [
5    .font: UIFont.systemFont(ofSize: 14)
6]))
7
8let label = UILabel()
9label.numberOfLines = 0
10label.attributedText = attributedText
11
12// Height calculation for attributed text
13let height = attributedText.boundingRect(
14    with: CGSize(width: 300, height: .greatestFiniteMagnitude),
15    options: [.usesLineFragmentOrigin, .usesFontLeading],
16    context: nil
17).height
18
19print("Attributed text height: \(ceil(height))")

1import SwiftUI
2
3struct ContentView: View {
4    var body: some View {
5        VStack(alignment: .leading) {
6            // Text automatically sizes to fit content
7            Text("This is a long text that will automatically wrap to multiple lines in SwiftUI. No configuration needed.")
8                .font(.body)
9                .padding()
10
11            // Fixed width with automatic height
12            Text("Another paragraph with more text content.")
13                .frame(maxWidth: .infinity, alignment: .leading)
14                .padding()
15        }
16    }
17}