Calculadora de Reconstituição
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
V = m / C_alvo
About this calculator
The Reconstitution Calculator is a practical tool to determine the volume of solvent needed to dissolve a known mass of solid solute to achieve a target concentration. Widely used in chemistry, pharmacy, and biology labs, it simplifies solution preparation and avoids manual calculation errors. Simply enter the solid mass (in grams, milligrams, etc.) and the desired concentration (in mg/mL, g/L, etc.) to get the exact solvent volume to add.
The calculation is based on the fundamental concentration formula: concentration = mass / volume. Rearranged, volume = mass / concentration. For example, to reconstitute 50 mg of a lyophilized powder to obtain a 10 mg/mL solution, the required volume is 50 / 10 = 5 mL of solvent. The calculator performs this division automatically, considering the units provided. It is crucial that mass and concentration units are compatible (e.g., g and g/L, or mg and mg/mL).
When to use? In preparing standard solutions for analysis, reconstituting lyophilized drugs in hospitals, diluting reagents for experiments, or any situation where a solid must be dissolved to a specific concentration. This tool is useful for professionals and students needing speed and accuracy.
Important precautions: always ensure the target concentration unit matches the mass unit (e.g., if mass is in mg, concentration should be in mg/mL). The calculator does not account for solvent density or volume changes due to dissolution. Also, reconstitution may require stirring or heating, but the calculated volume is the final solvent volume to add, not the total solution volume (solute volume is usually negligible).
Frequently asked questions
Can I use any mass and concentration units?
Yes, as long as they are compatible. For example, if mass is in grams, concentration should be in g/L or mg/mL (with proper conversion). The calculator does not automatically convert between different units.
Is the calculated volume the final solution volume?
No, it is the volume of solvent to add to the solid. The final solution volume is approximately equal to the solvent volume, as the solid volume is usually negligible. At high concentrations, there may be a slight variation.
What if I want to prepare a specific final volume, not a concentration?
This calculator is for reconstitution (known mass, target concentration). To prepare a final volume at a specific concentration, use a dilution calculator or the formula mass = concentration x volume.
Does the calculator work for any solvent?
Yes, the formula is solvent-independent. However, ensure the solid's solubility in the solvent is sufficient for the target concentration. The calculator does not check solubility.
Do I need to consider the purity of the solid?
The calculator assumes 100% purity. If purity is lower, adjust the effective mass (actual mass x purity) before using.