diff --git a/test/test_option_callback.py b/test/test_option_callback.py
index 843ae30..53b896f 100644
--- a/test/test_option_callback.py
+++ b/test/test_option_callback.py
@@ -8,7 +8,7 @@ from tiramisu.config import KernelConfig
 from tiramisu.setting import groups, owners
 from tiramisu import ChoiceOption, BoolOption, IntOption, FloatOption, \
     StrOption, OptionDescription, SymLinkOption, IPOption, NetmaskOption, Leadership, \
-    undefined, Params, ParamOption, ParamValue, ParamContext
+    undefined, Params, ParamOption, ParamValue, ParamContext, calc_value
 from tiramisu.api import TIRAMISU_VERSION
 from tiramisu.error import PropertiesOptionError, ConflictError, LeadershipError, ConfigError
 from tiramisu.i18n import _
@@ -1194,3 +1194,100 @@ def test_callback_raise():
         api.option('od2.opt2').value.get()
     except ConfigError as err:
         assert '"Option 2"' in str(err)
+
+
+def test_calc_value_simple():
+    val1 = StrOption('val1', '', 'val1')
+    val2 = StrOption('val2', '', callback=calc_value, callback_params=Params(ParamOption(val1)))
+    od = OptionDescription('root', '', [val1, val2])
+    cfg = Config(od)
+    assert cfg.value.dict() == {'val1': 'val1', 'val2': 'val1'}
+
+
+def test_calc_value_multi():
+    val1 = StrOption('val1', "", 'val1')
+    val2 = StrOption('val2', "", 'val2')
+    val3 = StrOption('val3', "", multi=True, callback=calc_value, callback_params=Params((ParamOption(val1), ParamOption(val2)), multi=ParamValue(True)))
+    od = OptionDescription('root', '', [val1, val2, val3])
+    cfg = Config(od)
+    assert cfg.value.dict() == {'val1': 'val1', 'val2': 'val2', 'val3': ['val1', 'val2']}
+
+
+def test_calc_value_disabled():
+    val1 = StrOption('val1', '', 'val1')
+    val2 = StrOption('val2', '', callback=calc_value, callback_params=Params(ParamOption(val1, True), default=ParamValue('default_value')))
+    od = OptionDescription('root', '', [val1, val2])
+    cfg = Config(od)
+    cfg.property.read_write()
+    assert cfg.value.dict() == {'val1': 'val1', 'val2': 'val1'}
+    cfg.option('val1').property.add('disabled')
+    assert cfg.value.dict() == {'val2': 'default_value'}
+
+
+def test_calc_value_condition():
+    boolean = BoolOption('boolean', '', True)
+    val1 = StrOption('val1', '', 'val1')
+    val2 = StrOption('val2', '', callback=calc_value, callback_params=Params(ParamOption(val1, True),
+                                                                             default=ParamValue('default_value'),
+                                                                             condition=ParamOption(boolean),
+                                                                             expected=ParamValue(True)))
+    od = OptionDescription('root', '', [boolean, val1, val2])
+    cfg = Config(od)
+    cfg.property.read_write()
+    assert cfg.value.dict() == {'boolean': True, 'val1': 'val1', 'val2': 'val1'}
+    cfg.option('boolean').value.set(False)
+    assert cfg.value.dict() == {'boolean': False, 'val1': 'val1', 'val2': 'default_value'}
+
+
+def test_calc_value_allow_none():
+    from tiramisu import calc_value, StrOption, OptionDescription, Config, Params, ParamOption, ParamValue
+    val1 = StrOption('val1', "", 'val1')
+    val2 = StrOption('val2', "")
+    val3 = StrOption('val3', "", multi=True, callback=calc_value, callback_params=Params((ParamOption(val1), ParamOption(val2)), multi=ParamValue(True), allow_none=ParamValue(True)))
+    od = OptionDescription('root', '', [val1, val2, val3])
+    cfg = Config(od)
+    assert cfg.value.dict() == {'val1': 'val1', 'val2': None, 'val3': ['val1', None]}
+
+
+def test_calc_value_remove_duplicate():
+    from tiramisu import calc_value, StrOption, OptionDescription, Config, Params, ParamOption, ParamValue
+    val1 = StrOption('val1', "", 'val1')
+    val2 = StrOption('val2', "", 'val1')
+    val3 = StrOption('val3', "", multi=True, callback=calc_value, callback_params=Params((ParamOption(val1), ParamOption(val2)), multi=ParamValue(True), remove_duplicate_value=ParamValue(True)))
+    od = OptionDescription('root', '', [val1, val2, val3])
+    cfg = Config(od)
+    assert cfg.value.dict() == {'val1': 'val1', 'val2': 'val1', 'val3': ['val1']}
+
+
+def test_calc_value_join():
+    from tiramisu import calc_value, StrOption, OptionDescription, Config, Params, ParamOption, ParamValue
+    val1 = StrOption('val1', "", 'val1')
+    val2 = StrOption('val2', "", 'val2')
+    val3 = StrOption('val3', "", callback=calc_value, callback_params=Params((ParamOption(val1), ParamOption(val2)), join=ParamValue('.')))
+    od = OptionDescription('root', '', [val1, val2, val3])
+    cfg = Config(od)
+    assert cfg.value.dict() == {'val1': 'val1', 'val2': 'val2', 'val3': 'val1.val2'}
+
+
+def test_calc_value_min():
+    from tiramisu import calc_value, StrOption, OptionDescription, Config, Params, ParamOption, ParamValue
+    val1 = StrOption('val1', "", 'val1')
+    val2 = StrOption('val2', "", 'val2')
+    val3 = StrOption('val3', "", 'val3')
+    val4 = StrOption('val4', "", callback=calc_value, callback_params=Params((ParamOption(val1), ParamOption(val2), ParamOption(val3, True)), join=ParamValue('.'), min_args_len=ParamValue(3)))
+    od = OptionDescription('root', '', [val1, val2, val3, val4])
+    cfg = Config(od)
+    cfg.property.read_write()
+    assert cfg.value.dict() == {'val1': 'val1', 'val2': 'val2', 'val3': 'val3', 'val4': 'val1.val2.val3'}
+    cfg.option('val3').property.add('disabled')
+    assert cfg.value.dict() == {'val1': 'val1', 'val2': 'val2', 'val4': ''}
+
+
+def test_calc_value_add():
+    from tiramisu import calc_value, IntOption, OptionDescription, Config, Params, ParamOption, ParamValue
+    val1 = IntOption('val1', "", 1)
+    val2 = IntOption('val2', "", 2)
+    val3 = IntOption('val3', "", callback=calc_value, callback_params=Params((ParamOption(val1), ParamOption(val2)), operator=ParamValue('add')))
+    od = OptionDescription('root', '', [val1, val2, val3])
+    cfg = Config(od)
+    assert cfg.value.dict() == {'val1': 1, 'val2': 2, 'val3': 3}
diff --git a/tiramisu/__init__.py b/tiramisu/__init__.py
index 4826832..db7fad8 100644
--- a/tiramisu/__init__.py
+++ b/tiramisu/__init__.py
@@ -13,7 +13,7 @@
 # You should have received a copy of the GNU Lesser General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 from .function import Params, ParamOption, ParamValue, ParamContext, \
-                      tiramisu_copy
+                      tiramisu_copy, calc_value
 from .option import *
 from .error import APIError
 from .api import Config, MetaConfig, GroupConfig, MixConfig
@@ -37,7 +37,8 @@ allfuncs = ['Params',
             'Storage',
             'list_sessions',
             'delete_session',
-            'tiramisu_copy']
+            'tiramisu_copy',
+            'calc_value']
 allfuncs.extend(all_options)
 del(all_options)
 __all__ = tuple(allfuncs)
diff --git a/tiramisu/function.py b/tiramisu/function.py
index 46bf1c0..94837a1 100644
--- a/tiramisu/function.py
+++ b/tiramisu/function.py
@@ -12,6 +12,9 @@
 #
 # You should have received a copy of the GNU Lesser General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
+from typing import Any, List, Optional
+from operator import add, mul, sub, truediv
+from .setting import undefined
 from .i18n import _
 
 
@@ -79,3 +82,235 @@ class ParamIndex(Param):
 
 def tiramisu_copy(val):  # pragma: no cover
     return val
+
+
+def calc_value(*args: List[Any],
+               multi: bool=False,
+               default: Any=undefined,
+               condition: Any=undefined,
+               expected: Any=undefined,
+               condition_operator: str='AND',
+               allow_none: bool=False,
+               remove_duplicate_value: bool=False,
+               join: Optional[str]=None,
+               min_args_len: Optional[int]=None,
+               operator: Optional[str]=None,
+               **kwargs) -> Any:
+    """calculate value
+    :param multi: value returns must be a list of value
+    :param default: default value if condition is not matched or if args is empty
+                    if there is more than one default value, set default_0, default_1, ...
+    :param condition: test if condition is equal to expected value
+                      if there is more than one condition, set condition_0, condition_1, ...
+    :param expected: value expected for all conditions
+                     if expected value is different between condition, set expected_0, expected_1, ...
+    :param condition_operator: OR or AND operator for condition
+    :param allow_none: if False, do not return list in None is present in list
+    :param remove_duplicate_value: if True, remote duplicated value
+    :param join: join all args with specified characters
+    :param min_args_len: if number of arguments is smaller than this value, return default value
+    :param operator: operator
+
+    examples:
+    * you want to copy value from an option to an other option:
+    >>> from tiramisu import calc_value, StrOption, OptionDescription, Config, Params, ParamOption
+    >>> val1 = StrOption('val1', '', 'val1')
+    >>> val2 = StrOption('val2', '', callback=calc_value, callback_params=Params(ParamOption(val1)))
+    >>> od = OptionDescription('root', '', [val1, val2])
+    >>> cfg = Config(od)
+    >>> cfg.value.dict()
+    {'val1': 'val1', 'val2': 'val1'}
+
+    * you want to copy values from two options in one multi option
+    >>> from tiramisu import calc_value, StrOption, OptionDescription, Config, Params, ParamOption, ParamValue
+    >>> val1 = StrOption('val1', "", 'val1')
+    >>> val2 = StrOption('val2', "", 'val2')
+    >>> val3 = StrOption('val3', "", multi=True, callback=calc_value, callback_params=Params((ParamOption(val1), ParamOption(val2)), multi=ParamValue(True)))
+    >>> od = OptionDescription('root', '', [val1, val2, val3])
+    >>> cfg = Config(od)
+    >>> cfg.value.dict()
+    {'val1': 'val1', 'val2': 'val2', 'val3': ['val1', 'val2']}
+
+    * you want to copy a value from an option is it not disabled, otherwise set 'default_value'
+    >>> from tiramisu import calc_value, StrOption, OptionDescription, Config, Params, ParamOption, ParamValue
+    >>> val1 = StrOption('val1', '', 'val1')
+    >>> val2 = StrOption('val2', '', callback=calc_value, callback_params=Params(ParamOption(val1, True), default=ParamValue('default_value')))
+    >>> od = OptionDescription('root', '', [val1, val2])
+    >>> cfg = Config(od)
+    >>> cfg.property.read_write()
+    >>> cfg.value.dict()
+    {'val1': 'val1', 'val2': 'val1'}
+    >>> cfg.option('val1').property.add('disabled')
+    >>> cfg.value.dict()
+    {'val2': 'default_value'}
+
+    * you want to copy value from an option is an other is True, otherwise set 'default_value'
+    >>> from tiramisu import calc_value, BoolOption, StrOption, OptionDescription, Config, Params, ParamOption, ParamValue
+    >>> boolean = BoolOption('boolean', '', True)
+    >>> val1 = StrOption('val1', '', 'val1')
+    >>> val2 = StrOption('val2', '', callback=calc_value, callback_params=Params(ParamOption(val1, True),
+    ...                                                                          default=ParamValue('default_value'),
+    ...                                                                          condition=ParamOption(boolean),
+    ...                                                                          expected=ParamValue(True)))
+    >>> od = OptionDescription('root', '', [boolean, val1, val2])
+    >>> cfg = Config(od)
+    >>> cfg.property.read_write()
+    >>> cfg.value.dict()
+    {'boolean': True, 'val1': 'val1', 'val2': 'val1'}
+    >>> cfg.option('boolean').value.set(False)
+    >>> cfg.value.dict()
+    {'boolean': False, 'val1': 'val1', 'val2': 'default_value'}
+
+    * you want to copy option even if None is present
+    >>> from tiramisu import calc_value, StrOption, OptionDescription, Config, Params, ParamOption, ParamValue
+    >>> val1 = StrOption('val1', "", 'val1')
+    >>> val2 = StrOption('val2', "")
+    >>> val3 = StrOption('val3', "", multi=True, callback=calc_value, callback_params=Params((ParamOption(val1), ParamOption(val2)), multi=ParamValue(True), allow_none=ParamValue(True)))
+    >>> od = OptionDescription('root', '', [val1, val2, val3])
+    >>> cfg = Config(od)
+    >>> cfg.value.dict()
+    {'val1': 'val1', 'val2': None, 'val3': ['val1', None]}
+
+    * you want uniq value
+    >>> from tiramisu import calc_value, StrOption, OptionDescription, Config, Params, ParamOption, ParamValue
+    >>> val1 = StrOption('val1', "", 'val1')
+    >>> val2 = StrOption('val2', "", 'val1')
+    >>> val3 = StrOption('val3', "", multi=True, callback=calc_value, callback_params=Params((ParamOption(val1), ParamOption(val2)), multi=ParamValue(True), remove_duplicate_value=ParamValue(True)))
+    >>> od = OptionDescription('root', '', [val1, val2, val3])
+    >>> cfg = Config(od)
+    >>> cfg.value.dict()
+    {'val1': 'val1', 'val2': 'val1', 'val3': ['val1']}
+
+
+    * you want to join two values with '.'
+    >>> from tiramisu import calc_value, StrOption, OptionDescription, Config, Params, ParamOption, ParamValue
+    >>> val1 = StrOption('val1', "", 'val1')
+    >>> val2 = StrOption('val2', "", 'val2')
+    >>> val3 = StrOption('val3', "", callback=calc_value, callback_params=Params((ParamOption(val1), ParamOption(val2)), join=ParamValue('.')))
+    >>> od = OptionDescription('root', '', [val1, val2, val3])
+    >>> cfg = Config(od)
+    >>> cfg.value.dict()
+    {'val1': 'val1', 'val2': 'val2', 'val3': 'val1.val2'}
+
+    * you want join three values, only if almost three values are set
+    >>> from tiramisu import calc_value, StrOption, OptionDescription, Config, Params, ParamOption, ParamValue
+    >>> val1 = StrOption('val1', "", 'val1')
+    >>> val2 = StrOption('val2', "", 'val2')
+    >>> val3 = StrOption('val3', "", 'val3')
+    >>> val4 = StrOption('val4', "", callback=calc_value, callback_params=Params((ParamOption(val1), ParamOption(val2), ParamOption(val3, True)), join=ParamValue('.'), min_args_len=ParamValue(3)))
+    >>> od = OptionDescription('root', '', [val1, val2, val3, val4])
+    >>> cfg = Config(od)
+    >>> cfg.property.read_write()
+    >>> cfg.value.dict()
+    {'val1': 'val1', 'val2': 'val2', 'val3': 'val3', 'val4': 'val1.val2.val3'}
+    >>> cfg.option('val3').property.add('disabled')
+    >>> cfg.value.dict()
+    {'val1': 'val1', 'val2': 'val2', 'val4': ''}
+
+    * you want to add all values
+    >>> from tiramisu import calc_value, IntOption, OptionDescription, Config, Params, ParamOption, ParamValue
+    >>> val1 = IntOption('val1', "", 1)
+    >>> val2 = IntOption('val2', "", 2)
+    >>> val3 = IntOption('val3', "", callback=calc_value, callback_params=Params((ParamOption(val1), ParamOption(val2)), operator=ParamValue('add')))
+    >>> od = OptionDescription('root', '', [val1, val2, val3])
+    >>> cfg = Config(od)
+    >>> cfg.value.dict()
+    {'val1': 1, 'val2': 2, 'val3': 3}
+
+    """
+    def value_from_kwargs(value: Any, pattern: str, to_dict: bool=False) -> Any:
+        # if value attribute exist return it's value
+        # otherwise pattern_0, pattern_1, ...
+        # otherwise undefined
+        if value is not undefined:
+            if to_dict == 'all':
+                returns = {0: value}
+            else:
+                returns = value
+        else:
+            kwargs_matches = {}
+            len_pattern = len(pattern)
+            for key in kwargs.keys():
+                if key.startswith(pattern):
+                    index = int(key[len_pattern:])
+                    kwargs_matches[index] = kwargs[key]
+            if not kwargs_matches:
+                return undefined
+            keys = sorted(kwargs_matches)
+            if to_dict:
+                returns = {}
+            else:
+                returns = []
+            for key in keys:
+                if to_dict:
+                    returns[key] = kwargs_matches[key]
+                else:
+                    returns.append(kwargs_matches[key])
+        return returns
+
+    def is_condition_matches():
+        calculated_conditions = value_from_kwargs(condition, 'condition_', to_dict='all')
+        if condition is not undefined:
+            is_matches = None
+            calculated_expected = value_from_kwargs(expected, 'expected_', to_dict=True)
+            for idx, calculated_condition in calculated_conditions.items():
+                if isinstance(calculated_expected, dict):
+                    current_matches = calculated_condition == calculated_expected[idx]
+                else:
+                    current_matches = calculated_condition == calculated_expected
+                if is_matches is None:
+                    is_matches = current_matches
+                elif condition_operator == 'AND':
+                    is_matches = is_matches and current_matches
+                elif condition_operator == 'OR':
+                    is_matches = is_matches or current_matches
+                else:
+                    raise ValueError(_('unexpected {} condition_operator in calc_value').format(condition_operator))
+        else:
+            is_matches = True
+        return is_matches
+
+    def get_value():
+        if not is_condition_matches():
+            # force to default
+            value = []
+        else:
+            value = list(args)
+        if min_args_len and not len(value) >= min_args_len:
+            value = []
+        if value == []:
+            # default value
+            new_default = value_from_kwargs(default, 'default_')
+            if new_default is not undefined:
+                if not isinstance(new_default, list):
+                    value = [new_default]
+                else:
+                    value = new_default
+        return value
+
+    value = get_value()
+    if not multi:
+        if join is not None:
+            value = join.join(value)
+        elif value and operator:
+            new_value = value[0]
+            op = {'mul': mul,
+                  'add': add,
+                  'div': truediv,
+                  'sub': sub}[operator]
+            for val in value[1:]:
+                new_value = op(new_value, val)
+            value = new_value
+        elif value == []:
+            value = None
+        else:
+            value = value[0]
+    elif None in value and not allow_none:
+        value = []
+    elif remove_duplicate_value:
+        new_value = []
+        for val in value:
+            if val not in new_value:
+                new_value.append(val)
+        value = new_value
+    return value