The Treasury has put the cost of the Canterbury earthquake at $4 billion.
In its first comprehensive estimate of the financial cost of the quake, it says the figure includes costs to businesses as well as households.
The Treasury says an earlier cost estimate of $2 billion was based on Earthquake Commission models.
The commission covers the first $100,000 of damage to houses and $20,000 for household contents.
Treasury's revised estimate includes costs to insurance companies of covering additional damage to households.
Treasury says the $4 billion bill will be partly offset by a boost to the economy from reconstruction work.
It expects the quake to have cut 0.5% from economic production in the September quarter. But the boost to gross domestic product will in the long run exceed the initial loss of production.
Christchurch Mayor Bob Parker says the revised figure paints a truer picture.