This paper presents high-precision radiocarbon age calibration for terrestrial and marine samples. The authors provide single-year and decadal radiocarbon tree-ring ages for the period cal AD 1510–1954, forming the basis of a detailed calibration curve. The Seattle decadal dataset, spanning back to 11,617 cal BP, is part of the integrated INTCAL98 calibration curve. Atmospheric radiocarbon ages are converted to global ocean radiocarbon ages using a carbon reservoir model. The INTCAL98 radiocarbon ages used in these calculations slightly differ from previously published ones. The paper discusses offsets, error multipliers, regional radiocarbon age differences, and marine radiocarbon age responses to oceanic and atmospheric forcing. The authors extended previous radiocarbon measurements back to 9668 cal BC and applied minor corrections to some radiocarbon ages. They also included corrected decadal and single-year radiocarbon ages for the intervals 6000 cal BC–cal AD 1950 and cal AD 1510–1954. The decadal data cover the 11,617–0 cal BP interval, while single-year data are given for the cal AD 1510–1954 interval. The paper discusses the radon correction applied to samples measured between 1977 and 1987. The 1993 correction was found to be too large, so the original radon correction was halved. The latest correction is small and has a limited effect. Adjustments to German oak and pine chronologies are included, with the pine series matched to the oak chronology. This yields a cal BP scale with a margin of error of about two decades. Regional offsets relative to Washington are reported, including Alaska, Russia, Tasmania, and South Chile. The paper also discusses laboratory offsets in pine and bristlecone pine data, showing substantial agreement between Seattle and Heidelberg measurements. The bristlecone pine radiocarbon age offset with Seattle oak ages is large and remains unexplained. Single-year radiocarbon calibration is discussed, with data from the Pacific Northwest and Kodiak Island. The inclusion of Kodiak Island data reduces the standard deviation of the cal AD 1884–1932 interval. Marine radiocarbon age calibration is also discussed, with a model-based marine curve still relevant. The paper presents a model for marine radiocarbon age calibration, considering ocean circulation and atmospheric radiocarbon production rates. The paper also discusses the implications of oceanic-induced changes in the marine reservoir age, noting that such changes cannot be excluded. The paper provides a comparison of marine radiocarbon ages derived from a carbon reservoir model and coral radiocarbon ages. The paper concludes with a summary of regional ΔR values and references to other studies on radiocarbon calibrationThis paper presents high-precision radiocarbon age calibration for terrestrial and marine samples. The authors provide single-year and decadal radiocarbon tree-ring ages for the period cal AD 1510–1954, forming the basis of a detailed calibration curve. The Seattle decadal dataset, spanning back to 11,617 cal BP, is part of the integrated INTCAL98 calibration curve. Atmospheric radiocarbon ages are converted to global ocean radiocarbon ages using a carbon reservoir model. The INTCAL98 radiocarbon ages used in these calculations slightly differ from previously published ones. The paper discusses offsets, error multipliers, regional radiocarbon age differences, and marine radiocarbon age responses to oceanic and atmospheric forcing. The authors extended previous radiocarbon measurements back to 9668 cal BC and applied minor corrections to some radiocarbon ages. They also included corrected decadal and single-year radiocarbon ages for the intervals 6000 cal BC–cal AD 1950 and cal AD 1510–1954. The decadal data cover the 11,617–0 cal BP interval, while single-year data are given for the cal AD 1510–1954 interval. The paper discusses the radon correction applied to samples measured between 1977 and 1987. The 1993 correction was found to be too large, so the original radon correction was halved. The latest correction is small and has a limited effect. Adjustments to German oak and pine chronologies are included, with the pine series matched to the oak chronology. This yields a cal BP scale with a margin of error of about two decades. Regional offsets relative to Washington are reported, including Alaska, Russia, Tasmania, and South Chile. The paper also discusses laboratory offsets in pine and bristlecone pine data, showing substantial agreement between Seattle and Heidelberg measurements. The bristlecone pine radiocarbon age offset with Seattle oak ages is large and remains unexplained. Single-year radiocarbon calibration is discussed, with data from the Pacific Northwest and Kodiak Island. The inclusion of Kodiak Island data reduces the standard deviation of the cal AD 1884–1932 interval. Marine radiocarbon age calibration is also discussed, with a model-based marine curve still relevant. The paper presents a model for marine radiocarbon age calibration, considering ocean circulation and atmospheric radiocarbon production rates. The paper also discusses the implications of oceanic-induced changes in the marine reservoir age, noting that such changes cannot be excluded. The paper provides a comparison of marine radiocarbon ages derived from a carbon reservoir model and coral radiocarbon ages. The paper concludes with a summary of regional ΔR values and references to other studies on radiocarbon calibration