System.Text.Base64Encoding.GetMaxCharCount C# (CSharp) Method

        public override int GetMaxCharCount(int byteCount)
        {
            if (byteCount < 0 || byteCount > int.MaxValue / 4 * 3 - 2)
                throw System.Runtime.Serialization.DiagnosticUtility.ExceptionUtility.ThrowHelperError(new ArgumentOutOfRangeException(nameof(byteCount), SR.Format(SR.ValueMustBeInRange, 0, int.MaxValue / 4 * 3 - 2)));
            return ((byteCount + 2) / 3) * 4;
        }