Drip emitter GPH: 0.5, 1, 2 or 4 GPH, colors and inlets

Short answer

An emitter's GPH (gallons per hour) is its maker's rating at a stated pressure, not a fixed number. Pick the flow your plants and layout need, check that your system pressure sits inside the emitter's rated range, and match the inlet (a 1/4 in barb, a 10-32 thread or 1/2 in FPT) to the part you are connecting it to.

Picks that fitAll picks and how to choose

Raindrip PC8050B 2 GPH pressure-compensating dripper (50‑pack)Check price on Amazon
Raindrip PC8010B 2 GPH pressure-compensating dripper (10‑pack)Check price on Amazon
Rain Bird SW10‑30PS 1.0 GPH pressure-compensating spot watering emitter (30‑pack)Check price on Amazon

What a GPH rating means

GPH is the water one emitter puts out in an hour. Makers publish it at a pressure. For an emitter that is not pressure-compensating, the flow moves when the pressure moves.

DIG rates its inline emitters at 0.5 and 1 GPH at 15 psi, and says their flow depends on the inlet pressure.^[1] So a "1 GPH" emitter on a 25 psi line does not put out the same water as on a 15 psi line. Read the pressure printed next to the flow.

Common ratings from the makers

Maker and line	Flows the maker lists	Pressure the maker lists	Pressure-compensating	Inlet
DIG standard button	0.5, 1, 2 GPH	15-25 PSI	No; flow rises with pressure	1/4 in barb
DIG PC button	0.5, 1, 2, 4 GPH	Compensates 7.25-58 PSI	Yes	1/4 in barb
DIG inline	0.5, 1 GPH at 15 psi	Flow changes with pressure	No	1/4 in barb at both ends
DIG PC4-DA	0.25, 0.5, 1 GPH per outlet	10-45 PSI	Yes	Four outlets; works with an arrow stake
Rain Bird PC on-line	Nine flows, 0.5 to 24 GPH	Compensates 15-50 psi	Yes	Self-piercing
Rain Bird Xeri-Bug	By model	15-50 psi	See the model	Barb, 10-32 thread or 1/2 in FPT

DIG lists its standard buttons at 0.5, 1 and 2 GPH for 15 to 25 PSI, with a flow table that rises with pressure.^[2] Its PC buttons come in 0.5, 1, 2 and 4 GPH and compensate between 7.25 and 58 PSI.^[3] The PC4-DA has four outlets at 0.25, 0.5 or 1 GPH each and works with an arrow stake.^[4]

Rain Bird's PC on-line emitters come in nine flows from 0.5 to 24 GPH and compensate from 15 to 50 psi.^[5] Its Xeri-Bug line comes with three inlet types, covered below.^[6]

Metric drippers are rated in liters per hour. Antelco describes its SPEC Drip as a pressure-compensating dripper in 2, 4 and 8 L/h with an outlet for 4 mm ID tubing.^[7] Antelco announced it in May 2026, and we could not establish that it is sold in the US or Canada.

Is a 2 GPH emitter the same as two 1 GPH emitters?

By arithmetic, the total flow is the same: two 1 GPH emitters put out 2 gallons an hour between them. What differs is where the water lands. Two emitters wet two spots.

Soil decides how much that matters. Utah State University Extension says soil texture controls how water moves through the soil, and suggests two emitters per perennial in sandy soil.^[8] DIG's FAQ likewise says water goes straight down in sandy soil.^[9] For pots, DIG suggests one or two 0.5 GPH drippers per pot.^[9]

What the colors mean

Colors are a maker's code, not an industry code. Raindrip colors its drippers red for 0.5 GPH, black for 1, green for 2 and yellow for 4.^[10] That mapping is Raindrip's only.

DIG shows why you cannot carry a code across lines. Its standard 0.5 GPH button is brown, its 1 GPH black and its 2 GPH green.^[2] Its inline emitters use red for 0.5 GPH and black for 1 GPH.^[1] Rain Bird says its PC on-line emitters have a color-coded outlet that shows the flow.^[5]

We could not read the emitter colors in DIG's G77AS kit manual, so we do not list them. When a part is loose in a bag, read the flow from the maker's page for that model, not from its color.

Inlets: barb, self-piercing, 10-32 and FPT

1/4 in barb. Pushes into 1/4 in tubing. DIG's button emitters have a 1/4 in barb inlet.^[2] See 1/4 in barbed connections.
Self-piercing. Rain Bird's PC on-line emitters pierce the tubing wall and have a barb outlet for 1/4 in tubing.^[5]
10-32 thread. A small threaded inlet. Rain Bird's Xeri-Bug comes in barb (XB-05PC, XB-10PC, XB-20PC), 10-32 thread (the -1032 models) and 1/2 in FPT (XBT-10, XBT-20) versions.^[6] See 10-32 threaded devices.
1/2 in FPT. A female pipe thread. Rain Bird offers the FPT Xeri-Bug only in 1.0 and 2.0 GPH.^[6]

Filtration goes with the emitter

Lower flows can need finer screens. DIG asks for 120 mesh on its 0.5 GPH PC button and 150 mesh for 1 GPH and up.^[3] Check the mesh before you mix flows on one head; the filter mesh guide explains the numbers.

Emitters that fit this decision

Picks that fit7 products

Choose by flow: the DIG bag of 100 is the 2 GPH green PC button, the DIG B224B 10-pack is the 4 GPH PC button, the Raindrip PC8050B (50-pack) and PC8010B (10-pack) are 2 GPH, the Raindrip PC4010B 10-pack is 1 GPH, the Rain Bird SW10-30PS is 1.0 GPH and the SW20-30PS is 2.0 GPH.

0.5, 1, 2 or 4 GPH: drip emitter flow, color codes and inlets