SettingsSettings for this calculationUS
The total volume of concrete being placed, in the unit shown.
Use the volume from the Concrete Calculator for your pour.
The fibre dosage rate, as mass per unit volume of concrete.
0.9-1.5 kg/m³ is typical for shrinkage/temperature crack control; structural (macro) fiber applications use much higher dosages (up to 9 kg/m³) — check your specific product's data sheet.
Fiber needed
26.3 lb
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
- 26.29 lb
They open the calculator with your figures already in it
Fiber-Reinforced Concrete (FRC) Dosage Calculator: 26.29 lb — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
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How this was calculated
Formula source(s)
- 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)
Inputs used
- Concrete Volume
- 13 yd³
- Fiber Dosage Rate
- 2.02 lb/yd³
Intermediate steps
- Equivalent in pounds
- 26.29 lb
Confidence note: 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.
What this calculation does not cover
- Only the dosage rate carries any information about the fiber itself. Length, denier, geometry and whether the product is monofilament, fibrillated or macro all change what a given kg/m³ actually delivers, and none of them are inputs. The rate has to come from the data sheet for the fiber being supplied.
- This is a purchase quantity, not a reinforcement design. It does not look at residual flexural strength, joint spacing, slab thickness or subgrade, and it cannot tell you whether fiber substitutes for bar. A jointless or structural fiber slab is designed against a residual-strength requirement measured on notched beams, and the dose falls out of that design rather than out of a volume multiplied by a rate.
- The answer is an exact mass for the exact volume typed: no waste allowance, no over-batching margin, and no rounding to whole bags. Fiber ships in pre-weighed bags sized to a batch, so what you actually order is bags per truck — round the mass up yourself against the bag size.
- The dosage rate is capped at 9 kg/m³ (0.56 pcf). That range covers micro-synthetic and structural synthetic macro fiber, but steel fiber doses used in jointless industrial floors sit well above it, and a rate typed above the cap is clamped down to 9 rather than refused.
- Nothing here covers what the fiber does to the pour. Mixing time and drum speed decide whether the fibers disperse or ball up, higher doses cut slump and can bring fiber to the surface, and the power-float window moves with them. Those sit with the ready-mix supplier and the finishing crew, not with this number.
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.
Computed in your browser — nothing you enter is uploaded. Presented in US customary units and US trade terminology. Where a formula follows a published standard, that standard and its edition are cited beside it on this page; where none governs, the page says so. Local amendments override model codes — verify against the code in force where you build.
Sources checked 2026-09-02 · in the site-wide review of 2026-09-06 · v1.2.1
Regulatory standards & verification citations1
- 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)
Which documents these citations point at
Standards referenced: ASTM C1116 (ASTM International, United States).
Cite this page
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