GPM to LPS Conversion Factor for Philippine Pump Specs

The direct conversion is fixed: 1 US gallon per minute (GPM) equals 0.0630902 liters per second (LPS). To convert GPM to LPS, multiply the GPM value by 0.0630902. To convert LPS back to GPM, divide by 0.0630902, or multiply by 15.8503. For a fast field check when you do not have a calculator on hand, divide GPM by 16: the result is accurate to within about 1.5 percent, close enough for a first pass at pump selection before you confirm with the exact factor.

A quick reference table removes the arithmetic entirely for common Philippine pump sizes: 5 GPM is 0.315 LPS, 10 GPM is 0.631 LPS, 20 GPM is 1.262 LPS, 50 GPM is 3.155 LPS, 100 GPM is 6.309 LPS, 200 GPM is 12.618 LPS, and 500 GPM is 31.545 LPS. The same table converts to m3/hr by multiplying the LPS figure by 3.6, since 1 LPS equals 3.6 m3/hr. These values matter most at the point of comparing a pump curve against a specified duty point. A pump datasheet stated in LPS and a project specification written in GPM are easy to mismatch by an order of magnitude if the conversion is rushed. Recheck the factor every time a specification changes hands between a mechanical engineer, a contractor, and a supplier, since each may default to a different unit convention.

Not every gallon is the same size. A US gallon is 3.785 liters, while an Imperial gallon (still used in some older UK-derived catalogs and older Philippine engineering references) is 4.546 liters. That difference changes the conversion factor: 1 US GPM equals 0.0630902 LPS, but 1 Imperial GPM equals 0.0757682 LPS, about 20 percent higher.

Most modern pump catalogs sold in the Philippines specify US gallons, since that is the convention used by pump brands manufactured to standards that dominate the local commercial pump market. But older specification sheets, some inherited plumbing plans, and certain European-standard pump curves still reference Imperial gallons. If a specification does not explicitly state which gallon it means, that is the first thing to confirm before converting, not after the pump has been ordered.

The practical risk: converting an Imperial GPM figure using the US factor understates the actual flow rate by about 20 percent, which can lead to selecting an undersized pump for a booster or transfer application. When in doubt, ask the pump brand's technical datasheet or the supplier directly which gallon standard the flow rate is stated in before finalizing a duty point.

Philippine pump specifications commonly appear in three different flow units depending on where the pump brand, the consulting engineer's training, or the plumbing code reference comes from: GPM, LPS, and m3/hr. None of these is wrong on its own, but mixing them without converting to a single common unit is where sizing errors happen.

The metric relationship: 1 m3/hr equals 0.2778 LPS, and 1 LPS equals 3.6 m3/hr. Combined with the GPM factor above, this lets you cross-check any pump duty point regardless of which unit the original document used.

JOHOB Hardware Trading supplies booster, transfer, and submersible pumping and pressure systems, including VFD duplex panel setups, sourced through an ISO 9001 certified partner factory and specified to the flow and head units in your project's mechanical drawings. Because our technical team routinely converts between GPM, LPS, and m3/hr when reviewing a request for quotation, we recommend sending us the original specification in whatever unit it was written in rather than pre-converting it yourself, so we can catch a unit mismatch before it becomes an undersized or oversized pump on site.

Flow rate is only half of a pump duty point. The other half is head (pressure), and that also needs a consistent unit before you size or quote a pump. The standard conversions: 1 bar equals 10.197 metres of water column (mWC), 1 psi equals 0.0689 bar, and 1 psi equals 0.7031 mWC. To go from psi directly to metres of head, multiply psi by 0.7031.

Philippine building specifications frequently state required pressure in psi at the topmost fixture, while pump curves from manufacturers are usually published in metres of head or bar. A specification that says 40 psi at the top floor needs to become roughly 28.1 mWC of required head before you can read it off a pump curve, and that head figure needs to include static lift, friction loss in the piping, and the pressure needed at the fixture itself, not just the pressure conversion alone. Our guide on how to size a booster pump for a commercial building walks through the head build up step by step, including static, residual, and friction components.

Combine this with the GPM to LPS conversion in the sections above and you have both halves of a duty point, flow rate and head, in the same units the pump curve uses. Getting both right before requesting a quotation is what lets a supplier return an accurate match on the first pass instead of a back-and-forth on units.

Say a mechanical specification calls for a booster pump rated at 150 US GPM at 45 psi, and you need to check that against a pump curve published in LPS and metres of head.

Flow: 150 GPM x 0.0630902 = 9.46 LPS.
Head: 45 psi x 0.7031 = 31.6 mWC (before adding static lift and friction loss for the specific riser).

With the duty point converted to 9.46 LPS at roughly 31.6 mWC plus system losses, you can now compare it directly against a metric pump curve, or hand these two numbers to a supplier for a like-for-like match instead of a GPM-and-psi figure that a metric catalog cannot be checked against directly. A duty of this size is normally handled as a duplex or triplex set from our commercial booster pumps range rather than a single pump, so the per pump flow is the total divided across the running units, with one unit on standby. This is the exact conversion step JOHOB Hardware Trading's technical team runs on every booster, transfer, and submersible pump request for quotation. Send the original specification, in whatever unit it was written, and we will convert, cross-check against the pump curve, and confirm the duty point back to you before quoting, typically within 1 business day of receiving the request. Our guide on when a VFD is worth it versus a fixed speed pump covers the control side of the same decision.

Once the duty point is converted and confirmed, the next step is getting a matched pump quoted without a second round of unit confusion. JOHOB Hardware Trading responds to requests for quotation within 1 business day, and pricing is quote-based since the correct pump, panel, and accessory combination depends on the confirmed duty point, not a fixed catalog price.

Standard lead times are 21 to 35 days for ex-stock booster, transfer, and submersible pump models, and 45 to 90 days for made-to-order configurations, including VFD duplex panel setups built around our VFD and control panel options. Coverage is nationwide across the Philippines: NCR, Luzon, Visayas, and Mindanao, including PEZA, SBMA, and Clark locations. VAT-registered buyers are billed with the standard 12 percent VAT; PEZA and SBMA locators and exporters qualify for zero-VAT invoicing.

To avoid a repeat of the unit-mismatch problem this guide is written to prevent, include both the original specification unit and your converted GPM, LPS, or m3/hr figure when you send a request for quotation, along with the piping, valves, and stainless steel flexible hose the installation needs. That lets our technical team verify the conversion independently before confirming a pump selection, rather than relying on a single conversion pass. Process duties like commercial laundry water requirements in the Philippines get the same unit restatement on the quotation.

• Guide: How to Size a Booster Pump
• Pumping and Pressure Systems
• Commercial Booster Pumps
• Guide: VFD vs Fixed-Speed Pumps
• Guide: Commercial Laundry Water Requirements
• Electrical Panels and Controls
• Water Storage Tanks

Reviewed: September 2026