Consumer sentiment in Japan was at its highest point in more than 13 years in August, the government said Friday.

The Cabinet Office said the unadjusted consumer confidence index for nationwide households, excluding single-person households, rose 0.5 point from July to 49.2, the highest reading since 49.4 in June 1991. The index gained 3.8 points to 48.7 in July.

The index is calculated by assigning points on the basis of whether consumers believe their confidence in employment, overall livelihood, income growth and inclination to purchase durable goods will "improve," "improve somewhat," "remain unchanged," "deteriorate somewhat" or "deteriorate" in the coming six months.

Regarding expectations for prices over the next year, 48.5 percent of all surveyed households, including single-person households, said they believe prices will remain unchanged, up from 46.2 percent in July.

The study found 39.2 percent expect a rise in prices, compared with 40.1 percent the previous month.