xolotl doesn't come with a automatic unit handling system like in NEURON, BRIAN, or in Julia, so you have to pay attention and make sure your parameters are in the right units. The following are default units for various parameters.

Variable Units
Length of compartment mm
Surface area of compartment
Volume of compartment
Voltage mV
Specific capacitance of membrane
Specific conductance of channel
Synaptic strength nS
Current injected into cell nA
Axial resistivity MΩ mm
Calcium concentration μM
temperature C