Rupiah Down, Prices Up? How Exchange Rates Reach the Shelf
4 min read
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4 min read
On 30 October 2026, the rupiah closed at Rp18.147 per US dollar, according to a daily market report on bernas.id seen through search. Shop prices did not jump that day. So does a weak rupiah really make everything cost more?
Yes, but slowly, and only in part. Economists call this exchange rate pass-through. It means how much of a currency move ends up in the price you pay. This post shows how it works with one simple example.
A company that imports flour, milk or parts pays in US dollars. When the rupiah gets weaker, each dollar costs more rupiah. The same shipment now costs more.
The company then has a choice. It can raise the shelf price. Or it can accept a smaller profit. Pass-through is the share of the extra cost that reaches your receipt.
A pass-through of 100% would mean every rupiah of extra cost lands on the price tag. In real life it is lower.
Take an invented product that sells for Rp100.000. Say Rp40.000 of that price pays for imported inputs. The other Rp60.000 covers local costs, wages and profit. All numbers here are NetWort arithmetic.
Now the dollar rises 10%, from Rp18.147 to about Rp19.962. That is a weaker rupiah.
| Case | Extra cost on imported part | New shelf price | Price change |
|---|---|---|---|
| Seller passes on all of it | +Rp4.000 | Rp104.000 | +4% |
| Seller passes on half | +Rp2.000 | Rp102.000 | +2% |
| Seller absorbs it all | 0 | Rp100.000 | 0% |
A 10% fall in the rupiah did not make the price 10% higher. At most it added 4%, because only 40% of the cost was imported.
Several things hold prices back.
Not everything is imported. Rent, wages and local ingredients are paid in rupiah. A weak rupiah does not change them.
Sellers fear losing customers. If competitors keep prices flat, a seller who raises prices may lose sales. So they often wait or cut margin first.
Stock bought earlier. A shop selling goods bought at the old rate has no new cost yet.
Contracts and hedges. Some firms locked in a rate in advance.
Studies give a range, not one number. One study of the Covid-era period (March 2020 to May 2022) found that a 1% rupiah fall raised consumer prices by about 0,24%, and wholesale prices by about 0,91% (Atlantis Press proceedings, seen through search summary only). The authors called the pass-through incomplete.
Notice the gap. Wholesale prices react far more than the prices you pay. That fits our example: the shelf price is only part imported cost.
Bank Indonesia's 2018 economic report also found that rupiah weakness had only limited effect on inflation in that period (Bank Indonesia, Economic Report 2018, Chapter 4, seen through search summary only). Results change by period, model and price measure, so treat 0,24% as a rough guide, not a rule.
Goods with a high imported share feel it first. Kontan reported that industrial sugar and wheat flour are almost fully imported, milk about 80% and soybeans about 97% (Kontan, via search summary). The food industry group Gapmmi said the effect depends on each company's imported share, and price talks with retailers often wait until a year-end review.
Energy matters too. Our post on the oil price shock and the rupiah shows another path from a weak currency to higher costs.
Inflation was 3,28% year on year in September 2026, according to Kontan and Investortrust reports seen through search. A weak rupiah is one risk that could push it up. Higher inflation can change what Bank Indonesia does with rates, and that moves bonds and stocks.
It also eats into cash. If prices rise 3% and your savings earn 2%, you lose buying power. See how inflation raises the cost of holding cash. To see why headline numbers can mislead, read about core vs headline inflation.
Open the NetWort Macro page. Look at the rupiah rate and inflation together. Ask one question: has inflation started to follow the currency, or not yet?