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Fiber-Reinforced Concrete (FRC) Dosage Calculator

Estimate the mass of synthetic (polypropylene) micro-fiber needed for a fiber-reinforced concrete pour.

Computed in your browser — nothing you enter is uploaded. Figures are presented for United States against IRC 2024, and every formula is cited under regulatory standards below.

Last verified 2026-08-27 · v1.2.0

Market
Imperial · sales tax

Fiber needed

26.46 lb

Check your inputs

Fiber dosage varies significantly by product and intended use (shrinkage control vs. structural reinforcement) — always follow the specific fiber manufacturer's technical data sheet for your project.

Equivalent in pounds
26.46 lb

For the dimensions entered, expect a fiber needed of 12 kg. Note that concrete volume sits at the low end of the range this calculator was checked against, so treat the output as indicative rather than settled. Moderate confidence — sound arithmetic, but allow for the variation any real site introduces. Set for United States against IRC 2024. The market selector changes both the units and the code cited.

Estimated cost — your price

This site holds no price list for this material — local prices vary too much to publish honestly. Enter your supplier's price and the result is costed with it.

Preliminary estimate, not certified engineering. This tool produces an indicative quantity calculation for planning purposes only — it is not a certified structural analysis, a guaranteed material takeoff, or a substitute for building department approval. Always verify measurements on-site and have a licensed contractor or structural engineer review any load-bearing, code-sensitive, or safety-critical work before purchasing materials or starting construction. Spotted an arithmetic or standards error? Report it to contact@craftquantities.com with your inputs — confirmed fixes become pinned regression tests.

[Schema Verified] Computed in alignment with American Concrete Institute (ACI 318-19) formulas and International Residential Code (IRC 2024) spatial boundaries.

Regulatory standards & verification citations

  • Typical polypropylene micro-synthetic fiber dosage for shrinkage/temperature crack control is 0.9-1.5 kg per m³ (1.5-2.5 lb per yd³), per common manufacturer technical data sheets (ASTM C1116 Type III fibers)

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Frequently asked questions

Do synthetic fibers replace rebar?
No — micro-synthetic fibers (this calculator) primarily control plastic shrinkage cracking, not structural load. Structural fiber reinforcement uses a different class of macro-fibers (steel or structural synthetic) at much higher dosages and doesn't substitute for rebar in most applications without an engineer's specific design.
How are fibers added to the mix?
Typically added directly to the ready-mix truck drum and mixed for several minutes at full drum speed before discharge — follow the manufacturer's mixing time recommendation.
Does fiber dosage affect workability?
Yes — higher dosages can reduce slump and workability, sometimes requiring a water-reducing admixture adjustment; discuss with your ready-mix supplier before specifying a high dosage.