Bilingual glossary · Updated 2026-10-25
Glossary: 120 calculation concepts, precisely defined
Six domains — finance, health, math & statistics, unit conversion, dev & computing, life & career. Every entry ships with a precise definition, the formula behind it, a worked numeric example, the most common misconception, and direct links into 1435 free calculators and 201 in-depth guides.
Finance & Money金融理财 · 28 terms
Compound Interest
复利
Interest earns interest, the exponential growth effect
Annual Percentage Rate (APR)
年化利率（APR）
The annualized cost of borrowing including fees
LPR (Loan Prime Rate)
LPR（贷款市场报价利率）
China’s monthly loan pricing benchmark
Equal Monthly Installment
等额本息
Fixed monthly payment, more total interest
Equal Principal Payment
等额本金
Fixed principal each month, declining payment, less interest
Rate Spread (Basis Points)
利率加点（BP）
The fixed spread added to LPR, fixed for the contract term
Housing Provident Fund Loan
公积金贷款
Policy low-rate mortgage with a quota cap
Individual Income Tax Threshold
个税起征点
The 5,000 yuan/month standard deduction — not the only exemption
Social Insurance + Housing Fund
五险一金
Five insurances plus housing fund contributions
Internal Rate of Return (IRR)
内部收益率（IRR）
The discount rate that makes NPV zero — the true yardstick of returns
Annuity
年金
A series of equal payments at equal intervals
Down Payment Ratio
首付比例
The upfront share of the home price
Annuity Factor
年金现值系数（Annuity Factor）
The factor that discounts a series of equal future payments into today's present value — the core constant behind monthly payments and pension math.
Yield to Maturity (YTM)
到期收益率（YTM）
The rate that discounts all of a bond's future cash flows to its current price — the true basis for comparing bonds.
Capitalization Rate
资本化率（Cap Rate）
Net operating income divided by property value — the yield of the property as a business.
Cash Flow
现金流（Cash Flow）
Actual money in and out, separate from profit; positive profit with negative cash flow can still bankrupt a company.
Compounding Frequency
计息频率（Compounding Frequency）
At the same nominal rate, more compounding periods mean higher real returns; 6% monthly compounding equals 6.17% annually.
Credit Score
征信分（Credit Score）
A lender's quantified probability that you repay on time; inquiries, utilization and delinquencies are inputs.
Currency Pair
货币对（Currency Pair）
How to read FX quotes: USD/CNY = 7.20 means 1 US dollar buys 7.20 yuan — read the direction carefully.
Debt-to-Asset Ratio
资产负债率（Debt Ratio）
Total liabilities over total assets; the healthy leverage band for firms and households runs roughly 50-70%.
Dividend Yield
股息率（Dividend Yield）
Dividend per share over price; a falling price inflates the yield — a high yield is not automatically a good company.
Maximum Drawdown
最大回撤（Max Drawdown）
The worst peak-to-trough decline; after a 50% drop you need a 100% gain to break even.
Emergency Fund
应急资金（Emergency Fund）
Three to six months of essential expenses held in instantly accessible form; the goal is liquidity, not yield.
Expense Ratio
基金费率（Expense Ratio）
Annual management + custody fees deducted from fund assets; a 1% gap eats about a quarter of your 30-year terminal value.
Fixed vs Floating Rate
固定利率与浮动利率（Fixed vs Floating）
Fixed locks certainty; floating follows the benchmark. Choosing one is a bet on future rates.
Inflation
通货膨胀（Inflation）
A sustained rise in the general price level; nominal return minus inflation is real purchasing-power growth.
Margin Call
追加保证金（Margin Call）
When account equity falls below the maintenance line you must add funds or cut positions — or be force-liquidated.
Net Asset Value (NAV)
基金净值（NAV）
The per-share asset value of a fund; NAV level says nothing about "expensiveness" or upside.
Health & Fitness健康运动 · 20 terms
Body Mass Index (BMI)
BMI（体质指数）
Weight over height squared — the universal screening metric
Basal Metabolic Rate (BMR)
基础代谢率（BMR）
The energy your body burns at complete rest
Resting Heart Rate
静息心率
Heartbeats per minute at rest — a window into cardiovascular health
Body Fat Percentage
体脂率
Fat mass as a share of body weight — closer to the truth than weight alone
Maximum Heart Rate
最大心率
The anchor for all training heart-rate zones
Calorie Deficit
热量缺口
Eating less than you burn — the mechanism behind all fat loss
Glycemic Index (GI)
血糖生成指数（GI）
How fast a food raises blood sugar
MET (Metabolic Equivalent)
MET（代谢当量）
Activity intensity as multiples of resting burn
Body Water Percentage
体水分率（Body Water）
Water as a share of body weight, roughly 50-65% for adults; muscle holds water, fat does not.
Creatinine
肌酐（Creatinine）
A muscle-metabolism waste product cleared by the kidneys; rising serum creatinine often signals declining kidney function.
Hemoglobin
血红蛋白（Hemoglobin）
The oxygen-carrying protein in red cells; 120-160 g/L for men and 110-150 for women — below the floor is anemia.
Hypertension Staging
高血压分级（Hypertension Staging）
Office blood pressure ≥140/90 mmHg defines hypertension; home readings use a lower line (≥135/85).
Ideal Weight
理想体重（Ideal Weight）
Height(cm) − 105 is a rough rule; the weight range mapping to BMI 18.5-23.9 is more scientific.
LDL and HDL Cholesterol
LDL 与 HDL（低/高密度脂蛋白）
LDL delivers cholesterol into vessel walls (bad); HDL hauls it back (good). LDL is the primary treatment target.
Metabolic Age
代谢年龄（Metabolic Age）
A "body age" back-solved from basal metabolic rate — a scale-maker's concept, useful as a trend, not a diagnosis.
Protein Intake
蛋白质摄入（Protein Intake）
General: 1.0-1.2 g/kg/day; muscle building: 1.6-2.2 g/kg/day; kidney disease requires medical restriction.
Sedentary Risk
久坐风险（Sedentary Risk）
Vascular function starts declining after ~1 hour of uninterrupted sitting; later exercise cannot fully offset it.
Sleep Cycle
睡眠周期（Sleep Cycle）
One cycle runs about 90 minutes (deep → light → REM); plan sleep in cycles rather than hours.
Steps per Day
每日步数（Steps per Day）
"10,000 steps" began as 1965 pedometer marketing; benefits plateau after 7,000-8,000 in most studies.
Uric Acid
尿酸（Uric Acid）
Above 420 μmol/L (men) or 360 (women) defines hyperuricemia; urate is the balance of purine intake and renal excretion.
Math & Statistics数学统计 · 22 terms
Standard Deviation
标准差
The typical distance of data points from the mean
Mean, Median and Mode
均值、中位数与众数
Three kinds of “average”, affected differently by outliers
Variance
方差
The average of squared deviations — standard deviation squared
Percentile
百分位数
Relative position within a distribution
Prime Number
质数
Integers divisible only by 1 and themselves — the atoms of number theory
GCD and LCM
最大公约数与最小公倍数
The largest common divisor and smallest common multiple
Probability
概率
The 0-to-1 scale of uncertainty
Geometric and Harmonic Mean
几何平均与调和平均
Use geometric for growth rates, harmonic for rates over fixed quantities
Arithmetic Sequence
等差数列（Arithmetic Sequence）
A sequence with constant differences; the sum is n × (first + last) ÷ 2.
Geometric Sequence
等比数列（Geometric Sequence）
A sequence with constant ratios; compounding, doubling growth and viral spread are all geometric.
Binomial Theorem
二项式定理（Binomial Theorem）
The coefficients of (a+b)^n are row n of Pascal's triangle — the bridge between probability and combinations.
Derivative
导数（Derivative）
The instantaneous rate of change (slope of the tangent) — the precise language of "how fast."
Euler's Number e
自然常数 e
e = 2.71828…, the unique base where y=e^x is its own derivative; the limit of continuous compounding.
Golden Ratio
黄金分割（Golden Ratio）
φ=(1+√5)/2≈1.618 with φ²=φ+1 — a real proportion in some places, a myth in many others.
Integral
积分（Integral）
A definite integral is the limit of infinitely fine summation — the area under a curve; the inverse of differentiation.
Logarithm
对数（Logarithm）
The inverse question of exponentiation — "what power gives this"; logs turn multiplication into addition.
Circle Area
圆面积（Circle Area）
A = πr² — double the diameter and area quadruples: why the large pizza is the better deal.
Percentage Change
百分比变化（Percentage Change）
Change = (new − old)/old; up 10% then down 10% does not return to start (−1% net).
Probability Basics
概率基础（Probability Basics）
P = favorable outcomes ÷ all equally likely outcomes; independent events multiply, mutually exclusive events add.
Scientific Notation
科学计数法（Scientific Notation）
a×10^n with 1≤|a|<10 — turning 0.0000000001 into 1×10⁻¹⁰ for clean writing and arithmetic.
Slope & Intercept
斜率与截距（Slope & Intercept）
y = kx + b: k is the change in y per unit x, b is the value at x = 0.
Unit Circle
单位圆（Unit Circle）
Points (cosθ, sinθ) on a radius-1 circle — the geometric home of trig functions and radians.
Units & Conversion单位换算 · 18 terms
Temperature Scales
温标
Celsius, Fahrenheit and Kelvin — three rulers for the same heat
Fahrenheit–Celsius Mental Conversion
华氏与摄氏的换算心算
Quick tricks for reading foreign weather and recipes
GB vs GiB
GB 与 GiB
Why your 1TB drive shows 931GB
Chinese Traditional Units
市制单位
Jin, liang, li, chi — and their exact SI conversions
Metric vs Imperial
公制与英制
A conversion map for the world’s last non-metric holdouts
Significant Figures
有效数字
Results can’t be more precise than the measurement
Acre & Hectare
英亩与公顷（Acre & Hectare）
1 hectare = 10,000 m² = 15 mu; 1 acre ≈ 4,047 m² ≈ 6.07 mu.
Celsius & Kelvin
摄氏与开尔文（Celsius & Kelvin）
K = C + 273.15 — same scale, different zero: 0 K is absolute zero, the standard language of physics and chemistry.
Cup & Gram
杯与克（Cup & Gram）
A US cup is 237 mL of volume; grams depend on the ingredient — flour 120g, sugar 200g, water 237g.
Foot & Inch
英尺与英寸（Foot & Inch）
1 foot = 12 inches = 30.48 cm; a 5'7" person is 170 cm.
GB and MB
GB 与 MB（数据单位）
1 GB = 1024 MB (binary) or 1000 MB (decimal) — a 7.4% gap between conventions.
Horsepower & Kilowatts
马力与千瓦（Horsepower & kW）
Metric horsepower: 1 PS ≈ 0.735 kW; US hp ≈ 0.746 kW. Motor nameplates and EV specs favor kW.
Knot & km/h
节与公里每小时（Knot & km/h）
1 knot = 1 nautical mile per hour ≈ 1.852 km/h — the standard speed at sea and in the air.
Liter & Gallon
升与加仑（Liter & Gallon）
A US gallon is 3.785 L; an imperial gallon 4.546 L — 20% apart. Ask which one before comparing fuel figures.
Lumen & Lux
流明与勒克斯（Lumen & Lux）
Lumens measure total light emitted; lux measures light arriving on a surface — lx = lm ÷ m².
Mbps vs MB/s
Mbps 与 MB/s（带宽与速度）
Carriers quote bits (b), download tools show bytes (B): 1 MB/s = 8 Mbps.
Nautical Mile
海里（Nautical Mile）
One nautical mile = 1,852 m = one minute of latitude; the distance language of sea and air.
Stone & Kilogram
英石与公斤（Stone & Kg）
1 stone = 14 pounds ≈ 6.35 kg — how the British report body weight.
Dev & Computing开发计算 · 14 terms
Byte vs Bit
字节与位（Byte vs Bit）
1 byte = 8 bits; bandwidth uses lowercase b (bit) while storage uses uppercase B (Byte) — an 8x difference.
Hexadecimal
十六进制（Hexadecimal）
A base-16 numeral system using 0-9 and A-F, where two hex digits map exactly to one byte.
Unix Timestamp
Unix 时间戳（Unix Timestamp）
Seconds (or milliseconds) elapsed since 1970-01-01 00:00:00 UTC — independent of any time zone.
UTF-8 Encoding
UTF-8 编码
Unicode's variable-length encoding: 1 byte for Latin letters, 3 for CJK characters, 4 for emoji — ASCII-compatible.
CRC Checksum
CRC 校验（Cyclic Redundancy Check）
A checksum computed via polynomial division, used to detect accidental corruption in transit or storage.
Baud Rate
波特率（Baud Rate）
Symbols transmitted per second; it equals bit rate only when each symbol carries one bit.
ASCII Table
ASCII 码表（ASCII Table）
128 numeric character codes: A=65, a=97, 0=48 — the 32 gap between cases is a bitwise Easter egg.
Base64 Encoding
Base64 编码（Base64）
Text-safe encoding of binary data over 64 characters; volume grows 4/3 — and it is not encryption.
BigInt & Numeric Precision
大数（BigInt 与精度上限）
JS's safe integer cap is 2^53−1 = 9,007,199,254,740,991 — beyond it, precision silently drops.
Boolean Algebra
布尔代数（Boolean Algebra）
The algebra of AND/OR/NOT — De Morgan's law (A·B)' = A' + B' is the master key for simplifying conditions.
Floating Point
浮点数（Floating Point）
Binary fractions approximate decimals imperfectly: 0.1+0.2≠0.3 is IEEE 754 by design, not a bug.
IPv4 & IPv6 Addresses
IPv4 与 IPv6 地址（IPv4 & IPv6）
IPv4's ~4.3 billion addresses are exhausted; IPv6's 128 bits offer effectively unlimited space.
Regular Expressions
正则表达式（Regex）
The micro-language of text matching: ^$ anchors, [] sets, +* quantifiers, () groups.
Timezone Offset
时区偏移（Timezone Offset）
UTC+8 means "8 hours ahead of UTC"; an instant and a local wall-clock time are different things.
Life & Career生活职场 · 18 terms
Leap Year
闰年（Leap Year）
A year divisible by 4 but not by 100 — unless also divisible by 400; February has 29 days.
Time Zones & UTC
时区与 UTC
UTC is the global reference; Beijing is UTC+8. Convert to UTC first for any cross-zone math.
Overtime Pay Base
加班费计算基数
Derived from the contractual monthly wage (no less than minimum wage), converted to hourly, then ×1.5/×2/×3.
Special Additional Deductions (Individual Income Tax)
个税专项附加扣除
Seven categories (child education, mortgage interest, etc.) deducted on top of the standard deduction to lower taxable income.
Mortgage Down-Payment Ratio
房贷首付比例
A lower ratio means higher leverage and heavier monthly payments; since 2024 many Chinese cities allow a 15% minimum for first homes.
Statutory Holidays
法定节假日
China has 13 statutory holiday days per year (from 2025); working them pays 3x and cannot be swapped for compensatory leave.
Average Wage: Which One?
平均工资口径
Urban non-private vs private, gross vs net, mean vs median — the numbers differ by nearly 2x depending on scope.
FX Mid Rate & Spread
汇率中间价与买卖价差
The mid rate is the central bank's reference; banks quote four rates around it — the real cost of FX hides in the spread.
Pregnancy Weight Gain
孕期体重增长（Pregnancy Weight Gain）
Guidelines scale by pre-pregnancy BMI: normal-weight women gain 11.5-16 kg total, ~0.42 kg/week in later trimesters.
Caffeine
咖啡因（Caffeine）
The adult ceiling is 400 mg/day; with a ~5-hour half-life, a 3 p.m. coffee is still half-present at midnight.
Commute Cost
通勤成本（Commute Cost）
Beyond fuel and fares: time priced at income means a 2-hour daily commute burns a month of salary a year.
Fuel Consumption
油耗（Fuel Consumption）
L/100km vs MPG: 235.2 ÷ MPG(US). Doubled fuel burn usually lives in driving habits, not the car.
Hourly-to-Salary Conversion
时薪与年薪换算（Hourly & Annual）
Hourly ≈ monthly × 12 ÷ (21.75×8); a bigger salary with longer hours can mean a lower true hourly rate.
Calories per Meal
一餐热量（Meal Calories）
Split the day 3:4:3 across meals; 500-700 kcal per meal covers most adults.
Lunar & Solar Calendars
农历与公历（Lunar & Solar Calendar）
The Chinese calendar is lunisolar: months follow the moon, farming terms follow the sun; New Year drifts within 19 days.
Night Shift & Circadian Rhythm
夜班与节律（Night Shift）
Circadian rhythm follows light: night workers can re-anchor with timed bright light and a fixed sleep window.
Retirement Age & Pension
退休年龄与养老金（Retirement Age & Pension）
Under gradual reform, male workers retire at 63; the pension sums a pooled basic benefit plus an individual-account annuity.
Rent vs Buy
租房与买房（Rent vs Buy）
When the rent-to-price ratio (monthly rent ÷ home price) falls below 1:600, renting wins on pure finance.