How It Works
This calculator works in 4 steps.
Enter the usable volume
Type the volume the wells or tubes actually receive.
Enter the dead volume
Type the unrecoverable volume from the reservoir or instrument spec.
Add overage
Type an optional percent for pipetting loss.
Read the preparation volume
The calculator returns total volume and the stock and diluent amounts for it.
The Formula
The formula adds the dead volume to the usable volume and applies any overage.
V_prep = (V_use + V_dead) × (1 + o)% dead = 100 × V_dead / V_use- V_use:
- Usable volume dispensed
- V_dead:
- Unrecoverable volume
- o:
- Optional overage fraction
A 96-well plate at 100 µL per well uses 9.6 mL. With a 1.5 mL reservoir dead volume, prepare 11.1 mL.
Conversion Table
The conversion table adds typical dead volumes to usable volumes for 6 container types.
| Container | Usable volume | Dead volume | Prepare | Dead share |
|---|---|---|---|---|
| Multichannel reservoir | 9.6 mL | 1.5 mL | 11.1 mL | 15.62% |
| 1.5 mL tube (manual) | 0.5 mL | 0.02 mL | 0.52 mL | 4% |
| Liquid handler trough | 20 mL | 5 mL | 25 mL | 25% |
| Acoustic source plate well | 0.03 mL | 0.015 mL | 0.045 mL | 50% |
| Dispenser bottle | 250 mL | 10 mL | 260 mL | 4% |
| Syringe pump line | 5 mL | 0.8 mL | 5.8 mL | 16% |
Dead volumes are examples. Use the value from the container or instrument documentation.
What Is the Dead Volume Allowance Calculator?
The Dead Volume Allowance Calculator is a tool that adds the volume left behind in a container, reservoir, or tubing, which cannot be aspirated, to the volume a dilution must supply. The result is the minimum volume to prepare.
Dead volume differs by format: a 1.5 mL tube leaves about 10 to 20 µL with careful pipetting, a multichannel reservoir leaves 1 to 3 mL, and a liquid handler trough leaves several mL. The user enters the dead volume from the container or instrument specification, and the calculator adds it to the usable volume.
Common Uses
There are 5 main uses of this calculator.
Reservoir filling
Users fill multichannel reservoirs with enough liquid for the last column.
Automation setup
Automation teams add trough and tip dead volumes to methods.
Expensive reagents
Labs pick low-dead-volume formats for costly antibodies.
Dispenser priming
Technicians include priming volume for bottle-top dispensers.
Kit sizing
Kit makers fill vials with dead volume included.