Estimate paddy rice yield using the standard yield components method: panicles per m², grains per panicle, fertility rate, and 1000-grain weight. Used by IRRI and national rice research programs.
Enter panicle density, grains per panicle, spikelet fertility, and 1000-grain weight to estimate rice yield in tons per hectare and bushels per acre.
Filled Grains/m² = Panicles/m² × Grains/Panicle × Fertility%
Yield (t/ha) = (Filled Grains/m² × 1000-Grain Weight g) ÷ 1,000,000
(1000-grain weight in grams; filled grains per m²; result in metric tons per hectare)
Yield (bu/acre) = Yield (t/ha) × 14.87 (rough rice conversion)
Irrigated rice: 300 panicles/m² × 120 grains × 85% fertility = 30,600 filled grains/m². At 25g 1000-grain weight: Yield = (30,600 × 25) ÷ 1,000,000 = 0.765 kg/m² = 7.65 t/ha = 113.8 bu/acre. For 1 ha: 7.65 tons.
1. Count panicles in 5-10 random 1m² quadrats at maturity. 2. Count grains on 10-20 representative panicles and average. 3. Estimate fertility (% filled vs empty spikelets). 4. Weigh 1000 grains (or use 20-28g typical for indica, 25-32g for japonica). Calculate.
Rice yield components are the standard method used by IRRI (International Rice Research Institute) and national programs for yield estimation before harvest. Typical yields: irrigated lowland 6-10 t/ha, rainfed lowland 2-4 t/ha, upland 1-3 t/ha. The Mekong Delta and Punjab achieve 8-10 t/ha; West African smallholders average 2-3 t/ha.
Counting panicles too early (before tillering stabilizes). Not accounting for sterile spikelets (fertility varies 60-95%). Using wrong 1000-grain weight (indica vs japonica differ). Forgetting moisture correction — yield is usually reported at 14% moisture.
✓ Expert Reviewed: This calculator and its content have been reviewed by agricultural experts. Formulas are based on standard extension service recommendations.