Methods and systems for diluting a dose of a substance to be delivered to a patient and for determining a maximum deliverable dose of the substance and/or a partial fluid volume to be delivered to the patient to provide a desired dose amount are provided. The method includes the step of providing a first substance within a fluid reservoir having an initial unit value. The method also includes diluting the first substance with a second substance to produce the diluted solution. Once the first substance is diluted, a total volume (VTotal) of the diluted solution is measured. A concentration of the diluted solution is then calculated based on the initial unit value and the total volume (VTotal). A fluid delivery system including a fluid reservoir and fluid delivery device, which is configured to perform the method, is also provided.
