Lime Requirement Calculator: Soil pH and Neutralizing Value
Calculate required Neutralizing Value (NV) and commercial liming materials (Lime, CaCO3) to correct soil acidity and optimize cation exchange.
Liming: how much lime you need to raise soil pH
The neutralising value needed (NV, in tonnes of CaO equivalent per hectare) = pH gap × 10 × soil buffer factor, then product tonnage = need ÷ (product NV ÷ 100). To raise a medium loam by one pH unit (5.6 to 6.6), the tool counts 2.8 t of CaO per hectare, i.e. 5.2 t of ground calcium carbonate with NV 54.
The tool's parameters
| Soil | t of CaO per 0.1 pH and per ha | Suggested target pH |
|---|---|---|
| Sandy | 0.15 | 6.2 |
| Sandy loam | 0.22 | 6.5 |
| Medium loam | 0.28 | 6.6 |
| Clay loam | 0.35 | 6.8 |
| Heavy clay | 0.45 | 7.0 |
Products offered: quicklime NV 95 (€180/t), calcium carbonate NV 54 (€45/t), dolomite NV 56 (€65/t), sugar beet lime NV 30 (€28/t). The number of passes is set so that no pass exceeds 1.5 t/ha of quicklime or 3.5 t/ha of the other products.
Worked example
18 ha of medium loam at pH 5.6, target 6.6: gap of 1 unit, 1 × 10 × 0.28 = 2.8 t of CaO/ha. With carbonate NV 54: 2.8 ÷ 0.54 = 5.19 t/ha, 93.3 t for the field, in 2 passes, €233/ha and €4,200 in total. With quicklime NV 95: 2.95 t/ha, 2 passes, €531/ha.
Limits
The buffer factor depends only on the texture you choose: the tool does not use organic matter, CEC or base saturation from your soil test, which refine the rate considerably. It does not separate corrective liming from annual maintenance, and the fineness of grinding, which governs how fast the product acts, is ignored. Default prices can be edited.
Sources and dates: buffer factors, target pH values, product NVs and prices, and per-pass limits are indicative values of the tool, not verified; NV is expressed in kilograms of CaO equivalent per 100 kg of product (checked 14/10/2026).
Frequently Asked Questions
What is the neutralising value (NV) of a liming product?
NV gives how many kilograms of CaO equivalent 100 kg of product supply. The tool uses 95 for quicklime, 54 for calcium carbonate, 56 for dolomite and 30 for sugar beet lime.
How much lime raises soil pH by one unit?
In the tool, one pH unit needs from 1.5 t of CaO per hectare on sandy soil to 4.5 t on heavy clay (2.8 t on medium loam). That is 5.2 t/ha of NV 54 carbonate for a medium loam.
How do I convert a CaO requirement into tonnes of product?
Divide the requirement by the product's NV ÷ 100: 2.8 t of CaO ÷ 0.54 = 5.19 t of calcium carbonate, or 2.8 ÷ 0.95 = 2.95 t of quicklime.
Can all the lime be spread in one pass?
The tool splits applications above 1.5 t/ha of quicklime or 3.5 t/ha of carbonate-based product per pass. 5.19 t/ha of carbonate is therefore spread in 2 passes.
Is this tool really free?
Yes, all tools on Kristools are 100% free and accessible without registration.
Is my data protected?
Yes. All processing is performed directly and securely inside your browser. No personal data is sent to our servers.