Size the mold and press
Move from parting-plane projection to clamp force and complete shot.
Home / Practical calculators for injection molding decisions
Injection molding workstation
Turn a process question into a traceable estimate.
A focused reference desk for machine sizing, shot planning, thermal timing, production output, and material cost. Start with the decision—not a generic tool directory.
Build a credible cycle
Use cooling, pack, motion, and ejection assumptions before forecasting output.
Check production exposure
Connect cavity output to resin use, scrap, utilization, and tooling allocation.
Core reference set
Pick a calculation by the constraint.
Six starting points covering machine, process, production, and material decisions.
View all toolsMachine sizing
Clamp Tonnage Calculator
Estimate injection molding clamp force from projected area and cavity pressure.
Machine sizing
Shot Size Calculator
Calculate injection molding shot weight including cavities, runner, and cushion.
Process
Injection Molding Cycle Time Calculator
Calculate total cycle time and cooling share.
Process
Cooling Time Calculator
Estimate cooling time using a flat-wall heat-transfer model.
Production
Parts Per Hour Calculator
Calculate injection molding production output from cycle time.
Costing
Material Cost Per Part Calculator
Estimate resin material cost per molded part.
Before the calculation
Bring one usable evidence record to the workstation.
PlasticsCalc is designed for a transparent first estimate: identify the record you have, run the linked calculation, then preserve the source and use the result to define the next validation step.
- Parting-plane record
- CAD projection, cavity count, runner projection, and a cavity-pressure basis lead to Projected Area and Clamp Tonnage. Confirm physical press and mold fit separately.
- Shot and process record
- Part and runner mass, cushion, resin basis, wall section, and an observed cycle lead to Shot Size, Cooling Time, and Cycle Time.
- Production and cost record
- Available hours, uptime, good-versus-scrap count, weighed mass, and purchase data lead to Parts Per Hour, Scrap Rate, and Material Cost.
Expanded workflow checks
Move from geometry to machine fit, output, and material planning
Cold-runner and sprue accounting
Document feed-system volume and mass before comparing the complete shot or material cost.
Machine sizing workflow
Screen clamp, injection unit, platen, tie-bar, and mold-height limits as separate checks.
Material planning workflow
Carry part mass, recovery policy, regrind approval, and purchase packaging into one traceable plan.
Process evidence
Process Validation & Stability Tools
Turn viscosity, cavity balance, pressure-drop, gate-seal and repeatability trials into traceable comparisons.
Measured energy evidence
Injection Molding Energy Measurement & Efficiency
Normalize a stable production run, keep press and peripheral boundaries visible, then screen idle windows, upgrade payback, and startup demand.
Part design evidence
Injection Molding Part Design & DFM Tools
Carry CAD wall, rib, boss and draft measurements into a documented feature review before tooling release.
New process workstation
Plastic Extrusion Setup & Line Balance
Measure actual output, translate final geometry into required throughput, compare screw speed, estimate material exposure, document tube drawdown, and plan cooling path.
New laboratory workstation
Plastic Film & Flexible Packaging Test Calculators
Reduce thin-film tensile, surface friction, seal peel, haze and transmittance, and five-level dart-impact measurements on a documented test basis.
