Thailand Toolkit

Water Bill Calculator

Estimate your Thai water bill from monthly usage, based on MWA's tiered residential rate.

Before you rely on this

Water rates are set by the Metropolitan Waterworks Authority (MWA) for Bangkok, Nonthaburi, and Samut Prakan, and can change. These figures come from MWA’s published tariff, not a rough estimate — check your actual bill for an exact figure.

Check your meter or a previous bill — usage is shown in cubic meters (m³).

Estimated monthly bill

฿166

Breakdown

0–30 m³ @ 8.50฿128
Raw-water charge฿2
Service charge฿25
VAT (7%)฿11
Total฿166

How this is calculated

  1. Your usage is split across 12 tiers, each billed at its own rate per cubic meter.
  2. A raw-water charge of ฿0.15 per cubic meter is added — this is collected on MWA’s bill on behalf of the Royal Irrigation Department.
  3. A monthly service charge is added (½″ meter, the size most homes use).
  4. 7% VAT is applied to the subtotal.

Frequently asked questions

Does this work outside Bangkok?

Not accurately — this uses MWA's rate for Bangkok, Nonthaburi, and Samut Prakan. The Provincial Waterworks Authority (PWA) serves the rest of the country with different rates.

Why does the rate increase with usage?

Thailand's residential water tariff is progressive, similar to electricity — the rate per cubic meter rises as your monthly usage climbs through each tier.