Many online embodied carbon calculator tools are designed specifically to help you figure this out.

• One Click LCA 
  • Affordability: Offers a free trial
  • Useful for: Embodied carbon comparison of individual materials, whole-building life-cycle analysis; LEED Building Life-Cycle Impact Reduction credit
• EC3
  • Affordability: Free tool
  • Useful for: Embodied carbon comparison of individual materials, LEED Procurement of Low-Carbon Construction Materials credit
• Athena Impact Estimator
  • Affordability: Free tool
  • Useful for: Whole-building life-cycle analysis
• CARE Tool
  • Affordability: Free tool 
  • Useful for: Estimating the operational and embodied carbon emissions associated with reusing and upgrading an existing building or replacing it with new construction.
• EPIC
  • Affordability: Free tool
  • Useful for: Evaluating tradeoff between embodied and operational carbon
• US EPA Waste Reduction Model (WARM)
  • Affordability: Free tool
  • Useful for: Calculating high-level baseline and alternative scenario estimates of greenhouse gas emissions reductions, energy savings and economic impacts of different waste management practices source reduction (can be adapted for reuse), recycling, composting, anaerobic digestion, combustion and landfilling.
• California Air Resources Board, Wood Reuse Calculator Tool (search "Reuse")
  • Affordability: Free tool
  • Useful for: "[Evaluating] carbon sequestration from reusing wood products and avoided GHG emissions from manufacturing of new wood products."
• Several other tools are listed on the Carbon Leadership Forum (CLF) pages here:
  • Carbon Leadership Forum (CLF) - Tools for Measuring Embodied Carbon

  • Carbon Leadership Forum (CLF) - End-of-Life Modeling and Data in North American Whole Building Life Cycle Assessment Tools