How does direct panicle count compare to transplanted hill counts?

Both methods calculate total panicles per unit area. In transplanted rice, panicles/ha equals hills/ha multiplied by productive tillers/hill. In direct-seeded or broadcast rice, growers place 0.25 m² or 1.0 m² sampling frames to count panicles directly, scaled to 10,000 m² per hectare.

What is rough rice versus milled rice?

Rough rice (also called paddy) includes the outer protective hull. All primary yield formulas calculate rough rice. Milled rice is the edible kernel remaining after hulling and polishing. The default 67% recovery is an editable planning assumption, not a guaranteed milling result; actual recovery depends on grain and mill conditions.

How are imperial units (cwt/acre and lbs/acre) derived?

One hectare equals approximately 2.47105 acres (1 acre = 0.404686 ha). Converting kg/ha to lbs/acre uses the exact conversion factor of 0.892179. In North America, rice is traded in hundredweight (cwt), where 1 cwt equals 100 pounds.

Why can yield component estimates differ from harvested receipts?

Component sampling estimates standing crop potential. Sampling error, harvest losses, lodging, threshing, grain moisture, and field-edge effects can make actual delivered weight different. Use representative samples and treat this result as a planning estimate.

What should I enter for 1,000-grain weight (TGW)?

Enter the measured weight of 1,000 representative filled grains from the crop being estimated. Variety, grain condition, and moisture affect this value, so a field or laboratory measurement is preferable to a generic preset.

Rice Yield Estimator

Estimate rough rice yield from field area, planting density or direct panicle counts, grains per panicle, and grain weight.

Crop & Yield Components

Stand Measurement Method

Transplanted (Hills) Direct Count (/m²)

Reference Variety Profile

Preset component values represent indicative agronomic baselines; adjust with field scouting data.

Field Area

Hills per Hectare

Use your field count, or calculate density from row and plant spacing below.

Productive Tillers per Hill

Count only productive tillers bearing panicles in representative hills.

Filled Grains per Panicle

Count only filled spikelets; exclude flat or sterile florets.

1,000-Grain Weight — TGW (grams)

Use clean rough paddy grains measured on a consistent moisture basis.

Planning Milling Recovery (%)

% milled

Editable planning assumption only. Actual milling recovery depends on grain condition and mill settings.

Rough Rice Price (per tonne paddy) (optional)

$ /t

Set yield components and click Estimate Yield to generate full field and per-unit production figures.

Estimated Rough Rice (Paddy) Yield

Pre-Harvest Potential

—

t / ha

—

kg / ha

—

cwt / acre

—

lbs / acre

Field Production Total

—

rough rice (tonnes)

—

hundredweight (cwt)

—

milled rice est. (t)

Milled rice is a planning estimate computed at 67% of rough paddy weight.

Field Component Density

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Panicles
/ m²

—

Panicles
/ ha (M)

—

Grains
/ ha (M)

—

Area Base
(ha / ac)

Factual Unit Relationships & Method Limitations

Standard Conversion Factors

• 1 hectare (ha) = 10,000 m² = 2.47105 acres

• 1 acre = 0.4046856 ha (4,046.86 m²)

• 1 kg/ha = 0.892179 lbs/acre

• 1 hundredweight (cwt) = 100 lbs rough rice

• 1 metric tonne (t) = 1,000 kg = 22.0462 cwt

Agronomic Pre-Harvest Limitations

• Pre-harvest estimate: Results reflect biological standing potential rather than combine hopper scale weight.

• Rough rice vs. milled: All base yields represent unhulled paddy. Commercial milling yield varies with grain fissures and mill settings.

• Moisture basis: Component weights rely on standardized air-dry seeds (~14% moisture basis).

Calculation Audit Breakdown

Calculation updated

Summary

Estimate rough rice yield from field area, planting density or direct panicle counts, grains per panicle, and grain weight.

How it works

Select your establishment method: Transplanted (hills/ha × tillers/hill) or Direct-Seeded / Field Count (panicles/m²).
Optionally select a rice reference preset or customize all component values.
Enter field area in hectares or acres.
Enter productive density: hills and tillers per hill, or measured panicles per square metre from representative quadrat frames.
Enter average filled grains per panicle and 1,000-grain weight (TGW) in grams.
Set the planning milling recovery percentage (default 67%) to inspect estimated milled rice volume.
Optionally enter rough rice price per tonne or per hundredweight (cwt) to evaluate gross revenue.
Click Estimate Yield to review yield intensity, total field production, unit relationships, and the calculation breakdown.

Use cases

Pre-harvest scouting across representative quadrants to project bin storage and drying logistics.
Comparing yield potential of transplanted versus broadcast or drill-seeded paddy stands.
Evaluating rough rice production in both international metric (t/ha) and North American commercial units (cwt/acre).
Assessing the yield impact of spikelet sterility or reduced grain filling from weather stress.
Classroom instruction and extension training on agronomic yield component relationships.
Planning commercial milling capacity using adjustable recovery planning rates.

Frequently Asked Questions

Last updated: 2026-09-22 · Reviewed by Nham Vu