The amount of the old-age basic pension is the amount obtained by multiplying 780,900 yen by the revision rate (meaning the rate set under the provisions of paragraph (1) of the following Article and revised under the provisions of that Article (excluding paragraph (1)) through Article 27-5; the same applies hereinafter) (if a fraction of less than 50 yen arises in that amount, it is to be rounded down, and if a fraction of 50 yen or more but less than 100 yen arises, it is to be rounded up to 100 yen). However, when paid to a person whose number of months of premium-paid periods is less than 480, the amount is the amount obtained by multiplying that amount by the number obtained by dividing the number of months obtained by combining the numbers of months listed in the following items (480 being the maximum) by 480.
The number of months of premium-paid periods;
保険料納付済期間の月数
A number of months corresponding to seven-eighths of the number of months of the one-quarter premium exemption period (the number of months obtained by deducting the number of months of premium-paid periods from 480 being the maximum);
保険料四分の一免除期間の月数（四百八十から保険料納付済期間の月数を控除して得た月数を限度とする。）の八分の七に相当する月数
A number of months corresponding to three-eighths of the number of months obtained by deducting, from the number of months of the one-quarter premium exemption period, the number of months of the one-quarter premium exemption period prescribed in the preceding item.
保険料四分の一免除期間の月数から前号に規定する保険料四分の一免除期間の月数を控除して得た月数の八分の三に相当する月数
A number of months corresponding to three-quarters of the number of months of half premium exemption periods (the number of months obtained by deducting, from 480, the number of months obtained by combining the number of months of premium-paid periods and the number of months of the one-quarter premium exemption period, being the maximum);
保険料半額免除期間の月数（四百八十から保険料納付済期間の月数及び保険料四分の一免除期間の月数を合算した月数を控除して得た月数を限度とする。）の四分の三に相当する月数
A number of months corresponding to one-quarter of the number of months obtained by deducting, from the number of months of half premium exemption periods, the number of months of half premium exemption periods prescribed in the preceding item;
A number of months corresponding to five-eighths of the number of months of the three-quarter premium exemption period (the number of months obtained by deducting, from 480, the number of months obtained by combining the number of months of premium-paid periods, the number of months of the one-quarter premium exemption period, and the number of months of half premium exemption periods, being the maximum);
保険料四分の三免除期間の月数（四百八十から保険料納付済期間の月数、保険料四分の一免除期間の月数及び保険料半額免除期間の月数を合算した月数を控除して得た月数を限度とする。）の八分の五に相当する月数
A number of months corresponding to one-eighth of the number of months obtained by deducting, from the number of months of the three-quarter premium exemption period, the number of months of the three-quarter premium exemption period prescribed in the preceding item;
保険料四分の三免除期間の月数から前号に規定する保険料四分の三免除期間の月数を控除して得た月数の八分の一に相当する月数
A number of months corresponding to one-half of the number of months of the full premium exemption period (excluding one relating to a premium that a person has been made not required to pay under the provisions of Article 90-3, paragraph (1)) (the number of months obtained by deducting, from 480, the number of months obtained by combining the number of months of premium-paid periods, the number of months of the one-quarter premium exemption period, the number of months of half premium exemption periods, and the number of months of the three-quarter premium exemption period, being the maximum).
保険料全額免除期間（第九十条の三第一項の規定により納付することを要しないものとされた保険料に係るものを除く。）の月数（四百八十から保険料納付済期間の月数、保険料四分の一免除期間の月数、保険料半額免除期間の月数及び保険料四分の三免除期間の月数を合算した月数を控除して得た月数を限度とする。）の二分の一に相当する月数
Read this with the articles around it
Revision, etc. of the Revision Rate
The revision rate in fiscal year 2004 is 1.
平成十六年度における改定率は、一とする。
Open this provisionRevision, etc. of the Revision Rate
The revision rate in fiscal year 2004 is 1.
平成十六年度における改定率は、一とする。
Open this provisionWith respect to the revision of the revision rate from the base fiscal year during the adjustment period, notwithstanding the provisions of the preceding Article…
調整期間における基準年度以後改定率の改定については、前条の規定にかかわらず、第一号に掲げる率に第二号に掲げる率を乗じて得た率（当該率が一を下回るときは、一。第三項第一号ロにおいて「基準年度以後算出率」という。）を基準とする。
Open this provisionAmount of the Pension
A number of months corresponding to seven-eighths of the number of months of the one-quarter premium exemption period…
保険料四分の一免除期間の月数（四百八十から保険料納付済期間の月数を控除して得た月数を限度とする。）の八分の七に相当する月数
Open this provisionAmount of the Pension
A number of months corresponding to three-quarters of the number of months of half premium exemption periods (the number of months obtained by deducting, from 480, the number of months obtained by…
保険料半額免除期間の月数（四百八十から保険料納付済期間の月数及び保険料四分の一免除期間の月数を合算した月数を控除して得た月数を限度とする。）の四分の三に相当する月数
Open this provisionAmount of the Pension
A number of months corresponding to five-eighths of the number of months of the three-quarter premium exemption period…
保険料四分の三免除期間の月数（四百八十から保険料納付済期間の月数、保険料四分の一免除期間の月数及び保険料半額免除期間の月数を合算した月数を控除して得た月数を限度とする。）の八分の五に相当する月数
Open this provisionWhere a request is made by an insured person who is a student, or an insured person, etc. who has been a student, who falls under any of the following items, the Minister of Health…
次の各号のいずれかに該当する学生等である被保険者又は学生等であつた被保険者等から申請があつたときは、厚生労働大臣は、その指定する期間（学生等である期間又は学生等であつた期間に限る。）に係る保険料につき、既に納付されたものを除き、これを納付することを要しないものとし、申請のあつた日以後…
Open this provisionpremium-paid periodmachine translation
「保険料納付済期間」
The time counted as paid up under Article 5, paragraph (1): time as a category 1 insured person (第一号被保険者) for which premiums were paid or collected in full, or did not have to be paid around childbirth (Article 88-2) or while raising a young child (Article 88-3, paragraphs (1) and (2)), together with all time as a category 2 (第二号被保険者) or category 3 insured person (第三号被保険者).
Defined inArticle 5, paragraph (1)
full premium exemption periodmachine translation
「保険料全額免除期間」
Time as a category 1 insured person (第一号被保険者) for which the whole premium did not have to be paid — by law under Article 89, paragraph (1), or on application under Article 90, paragraph (1) or the student rule of Article 90-3, paragraph (1) — other than months later paid up by retroactive payment (追納) under Article 94.
Defined inArticle 5, paragraph (3)
three-quarter premium exemption periodmachine translation
「保険料四分の三免除期間」
Time as a category 1 insured person (第一号被保険者) for which three quarters of the premium did not have to be paid under Article 90-2, paragraph (1) and the other quarter was paid, other than months later paid up by retroactive payment (追納) under Article 94.
Defined inArticle 5, paragraph (4)
half premium exemption periodmachine translation
「保険料半額免除期間」
Time as a category 1 insured person (第一号被保険者) for which half the premium did not have to be paid under Article 90-2, paragraph (2) and the other half was paid, other than months later paid up by retroactive payment (追納) under Article 94.
Defined inArticle 5, paragraph (5)
one-quarter premium exemption periodmachine translation
「保険料四分の一免除期間」
Time as a category 1 insured person (第一号被保険者) for which a quarter of the premium did not have to be paid under Article 90-2, paragraph (3) and the other three quarters were paid, other than months later paid up by retroactive payment (追納) under Article 94.
Defined inArticle 5, paragraph (6)
revision ratemachine translation
「改定率」
The rate, set at 1 for fiscal 2004 and revised each year under Articles 27-2 to 27-5 in line with prices and wages (with an adjustment during the adjustment period (調整期間)), by which the base amounts of pensions under this Act — such as 780,900 yen for the old-age basic pension (老齢基礎年金) — are multiplied.
Defined inArticle 27, paragraph (1)