An open-air research plot using infrared heaters to study the impact of climate warming on plant development and ecosystem stress.
serge-msc-uef-infrared-heaters-birch-climate-warming.jpg
The scientist behind plantbio
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Tools & Calculators

Free, science-based calculators for growers, built by a plant scientist
Built and checked by Serge, MSc, plant biologist and environmental scientist, grounded in hands-on research.
What are these tools? A set of calculators I built to answer the everyday number questions in gardening, hydroponics, and soil care. Each one uses established science and cites government and university extension sources. They are for educational purposes and give practical guidance, not professional advice.

Soil & Compost

Soil for a raised bed or pot

Soil Volume Calculator

Work out how much soil to fill a raised bed or pot, in litres, cubic feet, and bags.

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Mulch spread over a garden bed

Mulch Calculator

Find how much mulch your bed needs at the right depth, with extension depth guidance.

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Soil pH adjustment with lime or sulfur

Soil pH Amendment Calculator

Estimate the lime to raise pH or sulfur to lower it, by soil type and area.

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Compost mix of browns and greens

Compost Ratio Calculator

Check your browns-to-greens mix against the balance compost microbes work best at.

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Planting & Houseplants

Plants spaced evenly in a garden bed

Plant Spacing Calculator

See how many plants fit a bed at a given spacing, and how many per square foot.

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Repotting a houseplant with fresh potting mix

Repotting Soil Calculator

Work out how much potting mix a pot needs before you open a bag.

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Feeding a houseplant with liquid fertiliser

Fertiliser Dilution Calculator

Turn a label dose into the exact feed for your watering can, at full, half, or quarter strength.

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Light reaching indoor plants

DLI Calculator

Turn a light-meter reading and hours of light into a daily light integral for your plants.

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Pest Control

Spraying a plant for pest control

Pest Spray Dilution Calculator

Mix neem oil, insecticidal soap, or horticultural oil to the right strength every time.

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Hydroponics & Aquascaping

Hydroponic nutrient strength, EC and PPM

EC to PPM Calculator

Convert nutrient strength between EC and PPM across the 500, 640, and 700 meter scales.

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Hydroponic reservoir nutrient solution

Reservoir EC Dilution Calculator

Work out exactly how much water to add to bring a too-strong reservoir down to target.

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Planted aquarium aquascape

Aquarium Volume & Substrate Calculator

Find your tank's real volume and the substrate needed for a planted setup.

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These tools give general estimates and conversions for educational purposes and do not replace professional horticultural, agronomic, or aquarist advice. Always follow product labels and, for soil work, base decisions on a proper soil test.