Additional allowance
Mistake: Entering 0.5 when you mean 50%.
Fix: Enter 50 for 50%; 0.5 represents 0.5%.
Calculators · Free
Pattern-to-casting mass planner
Estimate metal charge from pattern mass and measured relative densities.
01Enter your values
Runs in your browserRuns offline in your browser. Once the page and required files have loaded, processing needs no internet.
02Pattern-to-casting mass planner
Runs in your browser
How it works
Estimate metal charge from pattern mass and measured relative densities.
mₙ = mₚ × ρₘ / ρₚ; mᵣ = mₙ × a / 100; mₜ = mₙ + mᵣ
Runs in your browser
Your data stays yours
Inputs are processed on this page and are never sent to a server.
About this tool
Use tool ↑Estimate metal charge from pattern mass and measured relative densities.
Multiply pattern mass by alloy density divided by pattern density. Add the chosen percentage of this net mass as reserve.
How to use it
- Enter your values
Pattern mass · Pattern relative density · Alloy relative density · Additional allowance
- Calculate / generate
Estimate metal charge from pattern mass and measured relative densities.
- Result
Total charge: 1.355263 kg
Calculation method
- Multiply pattern mass by alloy density divided by pattern density.
- Add the chosen percentage of this net mass as reserve.
mₙ = mₚ × ρₘ / ρₚ; mᵣ = mₙ × a / 100; mₜ = mₙ + mᵣ
Pattern-to-casting mass planner
- Pattern mass
- 0.1 kg
- Pattern relative density
- 0.95
- Alloy relative density
- 10.3
- Additional allowance
- 25 %
Result
Total charge: 1.355263 kg
Frequently asked questions
Assumptions and mistakes
Use relative densities measured against the same reference water and conditions, not different units or guessed metal presets. Add sprues to the pattern mass if required. Reserve is a percentage of net casting mass, not total charge. Thermal shrinkage, porosity and losses are not predicted; this is not a guaranteed casting recipe.
Where does my data go?
Calculations run on your device. Form inputs are not sent to a server.
Terms and definitions
Enter your values
- Measurement system
The initial choice follows your browser region. Your choice is remembered on this device. Gallons are US gallons. Switching units keeps your numbers unchanged and interprets them in the new unit.
Numbers stay unchanged. Check the new unit and enter the intended measurement, or select an example for that system.
- Pattern mass
Multiply pattern mass by alloy density divided by pattern density.
Enter a numerical value for this quantity. Use the unit shown beside this field. kg / lb
Minimum: 0.000001 · Maximum: 1000000 kg
- Pattern relative density
Multiply pattern mass by alloy density divided by pattern density.
Enter a numerical value for this quantity.
Minimum: 0.000001 · Maximum: 100
- Alloy relative density
Multiply pattern mass by alloy density divided by pattern density.
Enter a numerical value for this quantity.
Minimum: 0.000001 · Maximum: 100
- Additional allowance
Enter a percentage, not its decimal fraction: 50 means 50%. Use the unit shown beside this field. %
Minimum: 0 · Maximum: 1000 %
Result
- Result
Multiply pattern mass by alloy density divided by pattern density. Add the chosen percentage of this net mass as reserve.
Calculated from your entries using the method below.
- Total charge
Multiply pattern mass by alloy density divided by pattern density. Add the chosen percentage of this net mass as reserve.
Calculated from your entries using the method below.
- Net casting mass
Multiply pattern mass by alloy density divided by pattern density.
Calculated from your entries using the method below.
- Reserve mass
Add the chosen percentage of this net mass as reserve.
Calculated from your entries using the method below.
- Value
Multiply pattern mass by alloy density divided by pattern density. Add the chosen percentage of this net mass as reserve.
Calculated from your entries using the method below.
- Unit
Multiply pattern mass by alloy density divided by pattern density. Add the chosen percentage of this net mass as reserve.
Calculated from your entries using the method below.
Common mistakes and quick fixes
Pattern mass · Additional allowance
Mistake: Changing units and assuming the entered numbers were converted.
Fix: Numbers stay unchanged. Check the new unit and enter the intended measurement, or select an example for that system.
Assumptions and mistakes
Mistake: Treating a result as valid outside the described scope.
Fix: Use relative densities measured against the same reference water and conditions, not different units or guessed metal presets. Add sprues to the pattern mass if required. Reserve is a percentage of net casting mass, not total charge. Thermal shrinkage, porosity and losses are not predicted; this is not a guaranteed casting recipe.
Limits and key assumptions
- Use relative densities measured against the same reference water and conditions, not different units or guessed metal presets. Add sprues to the pattern mass if required. Reserve is a percentage of net casting mass, not total charge. Thermal shrinkage, porosity and losses are not predicted; this is not a guaranteed casting recipe.
- Displayed results may be rounded; rounding does not add measurement precision.