Advanced calculator
Enter Stock and Target Details
Formula Used
Unit conversion: 1 mg/mL = 1 µg/µL.
Stock conversion: stock in µg/µL = value × unit factor.
Dilution equation: C1V1 = C2V2.
Stock volume: V1 = (C2 × V2) ÷ C1.
Diluent volume: diluent = final volume − stock volume.
Dilution factor: factor = C1 ÷ C2.
For 100 mg/ml, the converted strength is 100 µg/µL.
How to Use This Calculator
- Enter the stock concentration shown on your solution label.
- Select the stock unit, such as mg/mL.
- Choose the unit for direct concentration conversion.
- Enter the desired target concentration and unit.
- Enter the final volume you need to prepare.
- Add overage when you need extra working solution.
- Choose serial steps for large dilution factors.
- Press the calculate button to view the result.
Example Data Table
| Stock | Converted Stock | Target | Final Volume | Stock Needed | Diluent Needed |
|---|---|---|---|---|---|
| 100 mg/mL | 100 µg/µL | 10 µg/µL | 100 µL | 10 µL | 90 µL |
| 100 mg/mL | 100 µg/µL | 5 µg/µL | 200 µL | 10 µL | 190 µL |
| 100 mg/mL | 100 µg/µL | 1 µg/µL | 1 mL | 10 µL | 990 µL |
Guide for Accurate Solution Dilution
Solution dilution turns a strong stock into a weaker working mix. The main idea is simple. The amount of solute stays constant. Only the liquid volume changes. This calculator helps when a stock is listed as mg/ml and a working value must be read in micrograms/microliter. These units look different, yet they are equal in scale. One mg/ml equals one microgram/microliter. So a 100 mg/ml stock equals 100 micrograms/microliter.
Why Unit Control Matters
Small unit errors can ruin a preparation. A missed prefix can change a dose by one thousand times. That can waste reagent. It can also damage a sample. Clear unit conversion removes that risk. The page converts stock strength first. Then it uses the converted strength in dilution math. This order keeps each step easy to audit.
Understanding the Dilution Step
A dilution has four core values. They are stock concentration, stock volume, target concentration, and final volume. The stock is the stronger solution. The target is the desired working concentration. The final volume is the amount you want to make. The calculator solves the missing stock volume with C1V1 equals C2V2. After that, it subtracts stock volume from final volume. The answer is the diluent volume.
Useful Lab Planning Options
Advanced options help practical work. Overage allows you to make extra solution. This is useful when pipette tips, tube walls, or transfers cause small losses. Serial dilution steps divide a large dilution factor into smaller moves. This can improve accuracy for very large reductions. Decimal control keeps results readable. The result table also shows converted stock strength and dilution factor.
Working With 100 mg/ml Stock
A 100 mg/ml stock is quite concentrated for many workflows. Since it equals 100 micrograms/microliter, the numbers stay simple. To make 100 microliters at 10 micrograms/microliter, use 10 microliters of stock. Add 90 microliters of diluent. The dilution factor is 10. If you add ten percent overage, the final planned volume becomes 110 microliters. Then the stock volume becomes 11 microliters.
Best Practices
Always check the stock label before mixing. Confirm the solvent is compatible. Use calibrated pipettes for small volumes. Label every tube with concentration, date, and initials. Record the calculation in a notebook. If the required stock volume is too small, prepare an intermediate dilution first. This reduces handling error. Review results before adding reagent. Careful dilution keeps laboratory measurements consistent and reliable.
Common Mistakes to Avoid
Do not mix mass units with volume units blindly. Convert every concentration into one base scale first. Avoid rounding too early. Early rounding can shift tiny pipetting values. Watch for labels written as ug/ml, mg/ml, ng/ul, or percent. They are not interchangeable. Also check whether the final volume includes stock. In dilution formulas, final volume means total mixture volume. It is not only the diluent amount in practice. Good records make repeated dilution work safer and faster.
Frequently Asked Questions
What is 100 mg/ml in micrograms/microliter?
It is 100 micrograms/microliter. The prefixes cancel evenly because one milligram has 1000 micrograms and one milliliter has 1000 microliters.
What does C1V1 equals C2V2 mean?
It means the solute amount remains constant during dilution. C1 is stock concentration. V1 is stock volume. C2 is target concentration. V2 is final volume.
Can this calculator handle units besides mg/ml?
Yes. It includes mg/mL, micrograms per microliter, micrograms per milliliter, nanograms per microliter, nanograms per milliliter, and grams per liter.
Does final volume include the stock solution?
Yes. Final volume means the total completed mixture. It includes both stock solution and diluent after everything is combined.
What is diluent volume?
Diluent volume is the amount of solvent, buffer, or water added to stock. It equals final volume minus stock volume.
Why is overage included?
Overage helps when some liquid is lost during handling. It is useful for tube walls, pipette tips, transfers, and repeated dispensing.
When should I use serial dilution steps?
Use serial steps when the direct stock volume is very small. Multiple smaller dilutions can reduce pipetting error and improve practical accuracy.
What happens when target concentration is stronger than stock?
The calculator shows an input warning. Dilution cannot make a solution stronger. You need a stronger stock or a concentration method.
Can I use this for biological solutions?
Yes, for mass per volume concentration. Always check reagent stability, solvent compatibility, sterility needs, and safety requirements before preparing samples.
Why are mg/ml and micrograms/microliter numerically equal?
Both numerator and denominator scale by 1000. The ratio stays unchanged, so 1 mg/mL equals 1 microgram/microliter.
Should I round before mixing?
Round only after reviewing all values. Early rounding can create errors, especially for very small stock volumes or large dilution factors.