# Phosphoric acid: Correlation Prices it moves with, and why Source page: https://www.materialinsights.org/chemicals/phosphoric_acid/correlation/ Phosphoric acid is made by dissolving phosphate rock in sulphuric acid. Most goes into DAP, MAP and other fertilisers, and purified grades into food, detergents and lithium iron phosphate batteries. Morocco, China and the United States dominate. The series is a US fertiliser index proxy. Proxy **US PPI: phosphoric acid, superphosphates and other phosphatic fertilizer materials** index (BLS base period) · monthly, Dec 2009 to Sep 2026 There is no free public price for phosphoric acid itself, so this tab uses the closest public series as a stand-in. Read the numbers as an indication, not as the price of this exact item. #### What its price moves with Selected link ##### Phosphoric acid and Phosphate rock Monthly changes 0.07 little or none correlation 12-month changes 0.54 moderate correlation Last 5 years -0.04 monthly changes Lead or lag −5 mo Phosphoric acid tends to lead by 5 months (r 0.40) Price function, Dec 2009 to Sep 2026 Phosphoric acid ≈ 13.1 × (Phosphate rock)^0.50 R² 0.61 On this fit, a 10% higher phosphate rock price goes with a 4.9% higher phosphoric acid price over the long run. Units: index (BLS base period) and $/mt. Chart: Phosphoric acid and Phosphate rock prices rebased to 100 at Dec 2009, log scale Both prices rebased to 100 at Dec 2009, on a log scale so equal percentage moves look the same size. Chart: Phosphoric acid price against Phosphate rock price, monthly, log scales, with fitted line Each dot is one month; paler dots are older (2009), darker dots recent (2026); the ringed dot is the latest month. The dashed line is the fitted price function. Both axes are logarithmic. Commodity [P Phosphate rock](https://www.materialinsights.org/commodities/phosphate/)Feedstock 0.07 Phosphate rock is the main raw material, and rock owners such as Morocco's OCP control much of the chain. The proxy shows a slow link: monthly moves correlate at 0.07, but yearly moves at 0.54, as rock contracts adjust over months. little or none co-movement month to month · 202 months Show charts Chemical [H2SO4 Sulphuric acid](https://www.materialinsights.org/chemicals/sulphuric_acid/)Feedstock 0.18 Sulphuric acid dissolves the rock, so sulphur and acid prices are a big cost for every producer without its own supply. Monthly moves correlate at 0.18 and yearly moves at 0.81, as costs pass through slowly. little or none co-movement month to month · 189 months Show charts Chemical [DAP DAP and MAP](https://www.materialinsights.org/chemicals/dap_map/)Derived product 0.34 Most phosphoric acid is reacted with ammonia to make DAP and MAP fertilisers. The proxy correlates at 0.34 for monthly moves and 0.88 for yearly moves, and at 0.52 for monthly moves in the last five years. weak co-movement month to month · 202 months Show charts Chemical [NH3 Ammonia](https://www.materialinsights.org/chemicals/ammonia/)Co-input 0.39 Ammonia is combined with phosphoric acid to make DAP and MAP, so both are priced off the same fertiliser cycle. The ammonia proxy is a US nitrogen fertiliser index; monthly moves correlate at 0.39 and yearly moves at 0.83. weak co-movement month to month · 202 months Show charts Energy [LFP Lithium iron phosphate batteries](https://www.materialinsights.org/energy/e_li_lfp/)Growing use 0.06 Purified phosphoric acid is used to make lithium iron phosphate battery cathodes, a fast growing demand. The battery index is a broad US price, and shows a weak link: monthly moves correlate at 0.06 and yearly moves at 0.31. little or none co-movement month to month · 196 months Show charts How to read these numbers **Correlation of monthly changes** (the number in the coloured pill) compares how much each price moved, month by month, since 2006 or the first month both series exist. It runs from −1 to +1: near +1 the two usually rise and fall in the same months, near 0 there is no link, and a negative number means they tend to move in opposite directions. Above 0.7 is strong, 0.4 to 0.7 moderate, 0.2 to 0.4 weak. **12-month changes** compare year-on-year moves, which shows whether two prices share the same cycles even when the month-to-month noise differs. **Price function** is a straight-line fit of the two prices on logarithmic scales: price ≈ k × (partner price)^β. β is how much this price moves, in per cent, for a 1% move in the partner over the whole period, and R² is the share of the variation the fit explains. Two prices that both drift up with inflation can fit well without any real link, so read it together with the monthly correlation. **Lead or lag** checks whether the monthly correlation is clearly higher when one price is shifted by 1 to 6 months. Correlation is not cause. The reasons on each card explain the economic link; the numbers show how strongly it has shown up in prices. Proxy series are US producer price indexes or related prices and can blur the real link. Data: World Bank Commodity Price Data (Pink Sheet), October 2026; US Bureau of Labor Statistics producer price indexes, IMF primary commodity prices and US EIA prices via FRED, Federal Reserve Bank of St. Louis, retrieved November 2026. Calculations by this site. ## Other sections - [Summary](https://www.materialinsights.org/chemicals/phosphoric_acid/index.md) - [Overview](https://www.materialinsights.org/chemicals/phosphoric_acid/overview/index.md) - [Production route](https://www.materialinsights.org/chemicals/phosphoric_acid/routes/index.md) - [Production](https://www.materialinsights.org/chemicals/phosphoric_acid/production/index.md) - [Feedstocks](https://www.materialinsights.org/chemicals/phosphoric_acid/feedstocks/index.md) - [Cycles](https://www.materialinsights.org/chemicals/phosphoric_acid/cycles/index.md) - [Trading](https://www.materialinsights.org/chemicals/phosphoric_acid/trading/index.md) - [Movement](https://www.materialinsights.org/chemicals/phosphoric_acid/movement/index.md) - [Regulation](https://www.materialinsights.org/chemicals/phosphoric_acid/regulation/index.md) - [Characteristics](https://www.materialinsights.org/chemicals/phosphoric_acid/characteristics/index.md) - [Emissions](https://www.materialinsights.org/chemicals/phosphoric_acid/emissions/index.md) - [Relationships](https://www.materialinsights.org/chemicals/phosphoric_acid/links/index.md)