Money Supply Doubling Time: 1.3 to 65.3 Years by Country

Money supply doubling time is the number of years a currency’s broad money stock takes to double, if it kept growing at its 10-year average rate. It is a description of the past decade, not a forecast. South Sudan doubles fastest among full-decade series, in 1.3 years (69.6%/yr, 2026-06). Dominica is slowest, at 65.3 years (1.07%/yr, 2026-02). No page currently ranking on this exact term is actually about doubling time — the top-10 search results return compound-interest calculators and inflation explainers with no monetary application. This page is the one that computes it, for 157 economies.

What Money Supply Doubling Time Means (and Doesn’t)

Doubling time answers one question: at a currency’s own average growth rate over the last ten years, how many years until its broad money stock is twice today’s size? Argentina’s 10-year CAGR is 62.8%/yr, so its broad money doubles in 1.4 years. Dominica’s is 1.07%/yr, so its doubling time runs to 65.3 years — a 46× spread between two live, dated numbers, not two abstract formulas. Nothing here forecasts the next decade. A 10-year CAGR describes the past ten years; doubling time is that same rate, expressed as a horizon instead of a percentage. It is built from CAGR only, never from YoY growth. A country’s most recent 12-month figure can run well above or below its own decade average. Swapping one in for the other produces a doubling time for a rate the economy hasn’t actually sustained. A related but distinct term some finance sites use is “money supply index.” That’s usually a rebased chart of the level itself (100 = a base year), not a growth rate. It isn’t the metric this page defines, though the two are often confused in casual use.

The audience’s own name for this number is “debasement rate” — the pace at which each existing unit of currency loses claim on real goods as new units are created. We publish the identical 10-year CAGR column under both labels, because readers arrive searching for either term and mean the same thing. Two other names describe the same underlying process from different angles: monetary dilution (the mechanism — more units chasing the same real output) and purchasing-power decay (the consequence — what a saved unit is worth later). All three point at the cagr10 column on our growth rate ranking, not three different numbers.

How We Calculate It: Exact Formula vs. Rule of 72

We compute doubling time as ln(2) ÷ ln(1 + CAGR) — the exact compound-growth formula — not the mental-math rule of 72 (72 divided by the growth rate as a whole number). At low growth rates the two nearly agree. Dominica’s 1.07%/yr gives 65.3 years exact against 67.5 years by rule of 72 — a 3.3% gap, small enough that the shortcut is a reasonable approximation for a currency-board economy. The two diverge hard once growth accelerates. South Sudan’s 69.6%/yr gives 1.31 years exact against 1.04 years by rule of 72 — a 21.1% underestimate. Push further, to Zimbabwe’s shortened-window 338.2%/yr, and rule of 72 gives 0.21 years against an exact 0.47 years — a 54.6% underestimate, more than double the real wait. The rule of 72 is a linear shortcut for a compound process; it holds up fine under about 15%/yr and fails increasingly badly above that, exactly where a debasement question actually gets interesting.

We set the base year for every CAGR ten years before an economy’s latest observation, not at a fixed calendar year. Türkiye’s 10-year CAGR compares 2026-02 against roughly 2016-02. Canada’s compares 2008 against roughly 1999, because 2008 is the newest figure we have for Canada. Every doubling time on this page inherits that same floating base year — full methodology covers how each economy’s window is set.

The Fastest and Slowest Money Supplies on Earth

Ranked by 10-year CAGR, South Sudan is the fastest growing money supply among full-decade series and Dominica is the slowest — a 65× spread on rate, and a 50× spread on doubling time. The table below spans both tails; the full 157-economy ranking, with every window and as-of date, lives on our growth-rate ranking and money supply by country pages.

Two entries carry no doubling time at all. Grenada’s growth rate is measurable only over the 13 months since a January 2025 series break. Gambia’s break sits one month before its only recent reading — too short a window for a rate of any kind, CAGR or YoY. A blank cell here is more honest than a number computed across a redenomination.

The Series-Break Warning: Six Countries, Shortened Windows

Six countries in our dataset carry a redenomination or unit-change break inside what would otherwise be a 10-year window. We attach the window to every rate we build from a shortened one, every time we state it. A rate with no window attached is not comparable to one that is. Zimbabwe’s IMF series drops by a factor of 1,727 in a single month, from 671,372,604,617 in April 2022 to 388,815,894 in May 2022 — a currency redenomination, not an economic collapse. Its 338.2% figure is real, annualized over the 47 months since that break, and it tops every ranking on this site by rate. It is not a 10-year rate, and a doubling time built on it — 5.6 months — describes what that specific 47-month pace would imply if it continued, not what the last decade actually did.

Equatorial Guinea’s break sits at 2018-05; its current 12.5%/yr CAGR covers the 5 years and 7 months since, through its latest 2023-12 reading, replacing a pre-fix calculation that read −3.9% by spanning the break. Grenada (break 2025-01) and Gambia (break 2025-10) have windows too short for any CAGR at all — 13 months and 1 month respectively — so we keep both outside every rate-based ranking on this site, doubling time included. Two more, Sierra Leone and Guinea-Bissau, carry breaks that predate their current 10-year window entirely, so their published rates (22.7%/yr and 5.7%/yr) are genuine full-decade figures despite the historical break. Presenting Zimbabwe’s 47-month rate and South Sudan’s full 10-year rate as the same kind of number would be exactly the error this site exists to catch on everyone else.

What Doubling Time Does Not Tell You

A fast doubling time is not an inflation forecast. Money-supply growth is a stock measure — the total currency and deposits in circulation. CPI inflation is a price index built from a separate basket of goods. The two correlate over long stretches, most visibly at the fast end of this page’s table. But they come from different data, and can diverge sharply within any single year. It is not a collapse timer either: Zimbabwe held double-digit money-supply growth for over a decade before its 2008 crisis, and Kuwait’s 38.8-year doubling time doesn’t make the dinar “safe” in any absolute sense, only slow-moving under its current peg. Every figure on this page is nominal, not inflation-adjusted. The real vs nominal money growth distinction matters most exactly where doubling time is shortest. A currency compounding at 60%/yr against 55%/yr CPI inflation is diluting real balances by a far smaller margin than the headline rate implies. Reading that gap needs both series, not one.

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