1)

Strip pricing as of December 31, 2017 for each of the first ten years and flat thereafter.

2)

Represents SEC and strip prices as of December 31, 2017 on a weighted average Appalachian index basis related to company-specific sales points.

Proved, Probable and Possible Reserves

Antero estimates that it had year-end 2017 3P reserves of 54.6 Tcfe, an 18% increase from year-end 2016. The 18% increase in 3P reserves was driven by a combination of increased type curves in certain areas driven by continued productivity gains from advanced completions, as well as 2017 leasehold acquisitions. As of December 31, 2017, the Company’s 54.6 Tcfe of 3P reserves were comprised of 75% natural gas, 23% NGLs and 2% oil. The Marcellus and Ohio Utica Shale comprised 48.3 Tcfe and 6.4 Tcfe of the 3P reserves, respectively. Virtually no Upper Devonian or West Virginia Utica reserves were included in 3P reserves.

Importantly, 46.2 Tcfe of Antero’s 48.3 Tcfe, or 96% of estimated Marcellus 3P reserves were classified as proved and probable reserves (“2P”), reflecting the low risk and statistically repeatable nature of Antero’s resource base. The 46.2 Tcfe of Marcellus 2P reserves includes 381 proved undeveloped and 460 probable locations, or 26% of the total undeveloped 2P reserve locations in the Marcellus that were booked at the approximate 2 Bcf/1,000′ type curve. This compares to year-end 2016 where 81 proved undeveloped and 7 probable locations, or just 3% of the total undeveloped 2P reserve locations in the Marcellus were booked at the approximate 2 Bcf/1,000′ type curve. The increase in upgraded 2P locations is primarily driven by continued productivity gains from implementing advanced completions techniques across a larger subset of Antero’s acreage position. Further, 6.2 Tcfe of Antero’s 6.4 Tcfe, or 97% of estimated 3P reserves in the Ohio Utica were classified as 2P.

The tables below summarize Antero’s estimated 3P reserve volumes as of December 31, 2017 using SEC pricing, categorized by operating area as well as PV-10 values of Antero’s 3P reserve volumes using both SEC and strip pricing. For further discussion of 3P reserves, please read “Non-GAAP Disclosure.”

Non-GAAP Disclosure

Certain selected financial information in this release is unaudited. Additional unaudited financial information will be provided in Antero’s Annual Report on Form 10-K for the year ended December 31, 2017, which the Company filed with the SEC on February 13, 2018. In this release, Antero has provided a number of unaudited metrics, which include all-in F&D cost per unit and proved developed F&D cost per unit. These non-GAAP metrics are commonly used in the exploration and production industry by companies, investors and analysts in order to measure a company’s ability of adding and developing reserves at a reasonable cost. The F&D costs per unit are statistical indicators that have limitations, including their predictive and comparative value. In addition, because the F&D costs per unit do not consider the cost or timing of future production of new reserves, such measures may not be adequate measures of value creation. These reserve metrics may not be comparable to similarly titled measurements used by other companies. There are no directly comparable financial measures presented in accordance with GAAP for all-in F&D cost per unit and proved developed F&D cost per unit, and therefore a reconciliation to GAAP is not practicable.

Calculations for all-in and proved developed F&D cost per unit are based on costs incurred in 2017. The calculations for both all-in and proved developed F&D cost per unit do not include future development costs required for the development of proved undeveloped reserves.

Pre-tax PV–10 values and pre-tax PV-10 values including hedges are non-GAAP financial measures as defined by the SEC. Antero believes that the presentation of these pre-tax PV–10 values are relevant and useful to its investors because it presents the discounted future net cash flows attributable to reserves and hedges prior to taking into account corporate future income taxes and the Company’s current tax structure. The Company further believes investors and creditors use pre-tax PV-10 values as a basis for comparison of the relative size and value of its reserves and hedges as compared with other companies. Antero believes that PV–10 estimates using strip pricing and including hedges can be used within the industry and by creditors and securities analysts to evaluate estimated net cash flows in the current commodity price environment. PV–10 estimates using strip pricing are not adjusted for the likelihood that the pricing scenario will occur, and thus they may not be comparable to PV–10 value using SEC pricing.

The GAAP financial measure most directly comparable to pre-tax PV–10 is the standardized measure of discounted future net cash flows (“Standardized Measure”). The following sets forth the estimated future net cash flows from our proved reserves (without giving effect to our commodity derivatives), the present value of those net cash flows before income tax (PV-10) and the present value of those net cash flows after income tax (Standardized measure) at December 31, 2017:

Notwithstanding their use for comparative purposes, the Company’s non-GAAP financial measures may not be comparable to similarly titled measures employed by other companies.

Antero has provided summations of its proved, probable and possible reserves and summations of its PV-10 for its proved, probable and possible reserves in this press release. The SEC strictly prohibits companies from aggregating proved, probable and possible reserves in filings with the SEC due to the different levels of certainty associated with each reserve category. Investors should be cautioned that estimates of PV-10 of probable reserves, as well as underlying volumetric estimates, are inherently more uncertain of being recovered and realized than comparable measures for proved reserves, and that the uncertainty for possible reserves is even more significant. Further, because estimates of probable and possible reserve volumes have not been adjusted for risk due to this uncertainty of recovery, their summation may be of limited use.