Ammonium sulphate: Correlation
Prices it moves with, and why
Ammonium sulphate is mostly a by-product of caprolactam and coke ovens, with some made directly from ammonia and sulphuric acid. It supplies both nitrogen and sulphur, and its price follows urea at a discount for its lower nitrogen content.
Proxy US PPI: nitrogenous fertilizer manufacturing index (BLS base period) · monthly, Jan 2006 to Sep 2026There is no free public price for ammonium sulphate 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 linkAmmonium sulphate and Caprolactam
Monthly changes 0.24 weak correlation 12-month changes 0.70 strong correlation Last 5 years 0.08 monthly changes Lead or lag +1 mo Caprolactam tends to lead by 1 month (r 0.29) Price function, Jan 2006 to Sep 2026 Ammonium sulphate ≈ 1.27 × (Caprolactam)1.07 R² 0.56 On this fit, a 10% higher caprolactam price goes with a 10.7% higher ammonium sulphate price over the long run. Units: index (BLS base period) and index (BLS base period).Chart: Ammonium sulphate and Caprolactam prices rebased to 100 at Jan 2006, log scale
Both prices rebased to 100 at Jan 2006, on a log scale so equal percentage moves look the same size.Chart: Ammonium sulphate price against Caprolactam price, monthly, log scales, with fitted line
Each dot is one month; paler dots are older (2006), darker dots recent (2026); the ringed dot is the latest month. The dashed line is the fitted price function. Both axes are logarithmic.Caprolactam plants produce ammonium sulphate whatever its price, so nylon demand rather than farm demand sets much of the supply. The cyclic intermediates proxy moves with the fertiliser proxy at 0.24 monthly and 0.70 yearly.
weak co-movement month to month · 249 months Show chartsPlants that make ammonium sulphate directly neutralise sulphuric acid with ammonia, so sulphur prices enter cost. The sulphuric acid index moves with the fertiliser proxy at 0.29 monthly and 0.90 yearly.
weak co-movement month to month · 225 months Show chartsAmmonia supplies the nitrogen in every route. Both share the same nitrogen fertiliser proxy here, so no separate statistics are shown for this pair. Ammonia prices still set the cost for plants that make the salt on purpose rather than as a by-product.
Not enough overlapping price history to measure.Farmers compare nitrogen fertilisers per unit of nitrogen, so urea sets a ceiling on ammonium sulphate, which earns a premium where soils need sulphur. Middle East urea moves with the proxy at 0.27 monthly and 0.82 yearly.
weak co-movement month to month · 249 months Show chartsCoke ovens for steelmaking recover ammonia from oven gas as ammonium sulphate, notably in China and India. The coal proxy moves with the fertiliser proxy at 0.22 monthly and 0.74 yearly, partly through the shared energy cycle.
weak co-movement month to month · 249 months Show chartsHow 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.