Nobody knows for certain how much oil has leaked into the Gulf of Mexico since last month’s oil rig explosion. What we do have are estimates – from the National Oceanic and Atmospheric Administration, from outside experts, from British Petroleum – of how fast crude is flowing out of two remaining leaks (a third was plugged Wednesday).

Oil has been flowing out of ruptures in the Deepwater Horizon well on the ocean floor since around 10 a.m. on April 22, two days after the BP-leased rig exploded, leaving 11 workers missing and presumed dead.

According to NOAA, an estimated 210,000 gallons (5,000 barrels) a day is coming from the remaining ruptures. At that rate, this leak would surpass the 11 million gallons spilled by the Exxon Valdez in 1989 in mid-June if left unchecked.

Other estimates are far more grim. The New York Times reported that BP told members of Congress the rate could be much, much higher:

In a closed-door briefing for members of Congress, a senior BP executive conceded Tuesday that the ruptured oil well could conceivably spill as much as 60,000 barrels a day of oil, more than 10 times the estimate of the current flow.

A barrel of crude oil contains roughly 42 gallons. In a follow-up story, the Times talked to a BP spokesman for more on the estimate:

“The rate could go up to that,” Mr. Suttles of BP said, when asked to verify a report in The Times. “It’s not the situation we have at this moment, but it’s not impossible.”

Based on this range of figures, we built the meter atop this post to give a ballpark figure of how much oil may have leaked into the Gulf based on each scenario (by multiplying the rate of leakage by the amount of time passed since the rupture) and other possible rates between those estimates.

At the low end is NOAA’s estimate of 210,000 gallons per day. At the high end is what BP told Congress. Drag the slider between those poles to see other possible rates. Keep in mind that all of this is only an estimate.

You can also embed this meter on your own site or blog. We’ll keep monitoring the situation and check on updates to our calculations as needed.

Editor’s Note: An earlier version of the text of this story included a reference to NOAA’s estimate as 210,000 barrels of oil per day. The correct measure is 210,000 gallons. This is an updated version.

Vanessa Dennis contributed to this report.

By: Chris Amico

PBS News website