Learn one useful thing today.
Add Decimal Minutes or Decimal Hours to a Clock Time (Midnight-Safe MOD)
Add or subtract decimal minutes (C2 / 1440) or decimal hours (C2 / 24) to any 24-hour clock time—wrapping cleanly across midnight without negative-time #### errors via MOD(..., 1).
Read the guide →TextAdd Leading Spaces & Indent Hierarchy Levels with REPT(" ", ...)
Create a visual hierarchy by prefixing labels with a validated number of spaces. Keep original labels and numeric levels for sorting and lookup.
Read the guide →TextAdd leading zeros to numbers: pad ZIP codes and IDs to fixed length
Pad numeric IDs with leading zeros to a target character width using REPT and MAX(0, ...) so longer codes are never truncated.
Read the guide →Text & String CleaningAdd Line Breaks in a Formula with CHAR(10) & TEXTJOIN (Multi-Line Address Labels)
Insert multi-line carriage breaks inside spreadsheet formulas using CHAR(10) and TEXTJOIN(CHAR(10), TRUE, ...) so blank apartment or suite rows collapse automatically without empty gap lines.
Read the guide →TextAdd line breaks with CHAR(10) and extract the last line in a cell
Join status updates with newline delimiter CHAR(10), count lines, and pull the most recent bottom line with TEXTAFTER(..., CHAR(10), -1).
Read the guide →Text & CleaningAdd OS-Specific Line Breaks: LF CHAR(10) vs. Windows/RFC-4180 CRLF Payloads
Assemble multi-line shipping addresses, EDI blocks, and RFC-4180 CSV cells using configurable LF (CHAR(10)) or CRLF (CHAR(13)&CHAR(10)) delimiters while skipping empty address lines.
Read the guide →Lookup & ReferenceAdd row numbers and skip blanks: sequential numbering with expanding COUNTA
Use IF(ISBLANK(B2), "", COUNTA($B$2:B2)) so populated items number 1, 2, 3 without gaps across blank spacer rows.
Read the guide →Dates & TimeAdd Workdays on a 6-Day (Mon–Sat) Custom Workweek (Skipping Sundays)
Calculate exact delivery, construction, or retail SLA deadlines on a 6-day Monday–Saturday schedule (skipping Sundays only) using universal closed-form weekday arithmetic A2 + B2 + INT((MOD(WEEKDAY(A2, 2), 7) + B2 - 1) / 6).
Read the guide →Date & TimeAdd years to a date: why EDATE(date, years*12) beats DATE on Feb 29 leap days
Compare EDATE(start, N*12) against DATE(YEAR(start)+N, MONTH(start), DAY(start)) for contract renewals and expiration dates.
Read the guide →Lookup & ReferenceADDRESS function: build A1 and sheet-qualified cell references from numbers
Convert 1-based row and column numbers into absolute, relative, or sheet-prefixed cell reference strings using ADDRESS.
Read the guide →FinanceAdjusted Present Value (APV): Unlevered Value, Tax Shield & Distress
Value leveraged buyouts (LBOs) and project-finance structures using Stewart Myers's Adjusted Present Value APV = V_Unlevered + PV(Interest_Tax_Shields) - PV(Financial_Distress).
Read the guide →Naval Architecture, Maritime Chartering & Propulsion EconomicsAdmiralty Coefficient, Hull Speed & Slow-Steaming Formula
Calculate Displacement Vessel Froude Hull Speed 1.34*SQRT(LWL_ft), Admiralty-Formula Shaft Power (Disp^(2/3) * V^3) / C_adm, Daily Bunker Consumption (t/day), and Slow-Steaming Voyage Fuel per 1,000 Nautical Miles.
Read the guide →Clinical Medicine & PhysiologyADO Index Calculator: Age, Dyspnoea & Airflow Obstruction 3-Year COPD Mortality Score
Calculate Milo Puhan et al.’s (2009, The Lancet) primary-care ADO Index (0–10 points) from Age decade, mMRC Dyspnoea (0–4), and Post-Bronchodilator FEV1 % Predicted — without requiring a 6-Minute Walk Test.
Read the guide →Statistical & Clinical AnalysisAdrogué-Madias Formula: Predicted Serum Sodium Change per Liter of IV Infusate
Calculate expected Δ[Na+] = ([Na+ + K+]_infusate - [Na+]_serum) / (TBW + 1) and required 3% hypertonic saline volume (mL) while guarding against osmotic demyelination.
Read the guide →Statistical & Clinical AnalysisAdult Appendicitis Score (AAS) Formula: Sammalkorpi Sex-Adjusted RLQ Triage
Calculate Heidi Sammalkorpi’s Adult Appendicitis Score (0–23 points) integrating sex/age-adjusted RLQ guarding, pain relocation, WBC, neutrophil %, and early vs. >= 24h CRP.
Read the guide →Healthcare & ClinicalAge-Adjusted Charlson Comorbidity Index (CCI) & 10-Year Survival Formula
Calculate the Age-Adjusted Charlson Comorbidity Index (adding +1 point per decade from age 50 up to +4 at age >= 80, plus 1-, 2-, 3-, and 6-point comorbidity weights) and estimated 10-year survival 100 * (0.983 ^ EXP(CCI * 0.9)).
Read the guide →Epidemiology & Healthcare Quality AnalyticsAge-Standardized Rate & SMR Simpson’s Paradox Formula
Resolve hospital mortality Simpson’s Paradox using Direct Age-Standardized Rate (DASR per 1,000) and Indirect Standardized Mortality Ratio SMR = Observed / Expected.
Read the guide →Structured Finance & Mortgage-Backed SecuritiesAgency MBS PSA Prepayment Ramp & Cashflow Formula
Calculate SIFMA PSA Seasoned Conditional Prepayment Rate (CPR), Monthly Single Monthly Mortality SMM = 1 - (1 - CPR)^(1/12), Unscheduled Principal on Post-Amortization Balance, and Total Principal.
Read the guide →Contract Theory & Corporate GovernanceAghion-Bolton Contingent Control & Covenant Formula
Model Philippe Aghion and Patrick Bolton’s (1992) incomplete-contract pecking order across entrepreneur control, debt-covenant state-contingent control, and investor control.
Read the guide →Mechanical Design & Power TransmissionAGMA Gear Pitting Contact Stress (sigma_c) and Elastic C_p Formula
Calculate AGMA elastic coefficient C_p and Hertzian gear-tooth surface pitting stress sigma_c = C_p * SQRT(W_t * K_all / (b * d_p * I_geom)) in Excel and Arte Sheets.
Read the guide →Statistical & Clinical AnalysisAgresti-Caffo "+1 Success, +1 Failure per Arm" Risk Difference 95% CI Formula
Replace degenerate small-sample Wald 2-proportion confidence intervals with Alan Agresti & Brian Caffo’s (2000) adjusted interval: add 1 pseudo-success and 1 pseudo-failure to EACH arm (p_tilde = (x + 1) / (n + 2)) before computing Wald bounds!
Read the guide →Statistical & Clinical AnalysisAgresti-Coull Binomial Confidence Interval ("Add 2 Successes & 2 Failures")
Replace erratic small-sample Wald intervals with Alan Agresti and Brent Coull’s (1998) z²-adjusted proportion center p̃ = (x + 0.5*z²) / (n + z²) and 95% confidence bounds.
Read the guide →Warehouse Automation, Intralogistics AGV / AMR Robotics & Fleet Dispatch EngineeringAGV & AMR Warehouse Fleet Sizing & Cycle Time Formula
Calculate Ideal Round-Trip Mission Time Including Deadhead & Docking (min), Net Effective Trips Per Robot Hour, Fractional AGV Requirement, and Rounded Integer Fleet Count.
Read the guide →Lookup, Reference & Dynamic ArraysAI Assistant Chart Creation: 7 Supported Chart Types, Explicit Ranges & Data Prep
Use Arte Sheets’ AI Assistant via text or voice to create column, bar, line, area, pie, doughnut, and scatter charts on explicit A1:C10 ranges (<= 10,000 cells, <= 50 charts/sheet, title <= 120 chars), and prepare clean summary tables for instant charting.
Read the guide →AI & AutomationAI Assistant Context Window Sizing: 40x12 Selection Scan, 160-Cell & 14 KB Caps
Audit how Arte Sheets scopes live worksheet context for AI Assistant text and voice prompts—scanning up to 40x12 selected cells plus A1:H12 headers within a 160-cell, 14,000-byte, and 30-sheet-tab budget.
Read the guide →Lookup & ReferenceAI Assistant File Attachments (.xlsx, .csv, .tsv, .txt): Safe Excerpt Import & Reconciliation
Attach vendor .xlsx, .csv, .tsv, or .txt statements (up to 2 MB) in Arte Sheets’ AI assistant to populate clean comparison ranges and reconcile invoice variances with COUNTIF and XLOOKUP.
Read the guide →Financial & AccountingAI Assistant in Suggest Mode: Collaborative Cell Suggestions, Role Checks & Proposal Audit
Understand how Arte Sheets routes AI formula and value edits as reviewable cell suggestions for suggester roles and suggest mode, blocks unreviewed style/structural mutations, and requires explicit owner confirmation before sending share invitations.
Read the guide →AI & CollaborationAI Assistant Role Matrix: Cell Suggestion Routing vs. Structural Command Guards
Audit how Arte Sheets routes AI cell edits into reviewable proposals for Suggesters while enforcing Owner/Contributor roles and <=100-cell / <=20-row limits on structural commands.
Read the guide →Lookup, Reference & Dynamic ArraysAI Assistant Sheet & Grid Commands: Add/Rename Tabs & 1-Based Row/Column Edits
Learn how Arte Sheets’ AI Assistant executes create_sheet, rename_sheet, select_sheet, and 1-based insert/delete row and column commands (1..20 count) with protected-sheet and role guardrails, plus write row-insertion-safe total formulas.
Read the guide →Financial & AccountingAI Cell Formatting, Number Formats & Data-Validation Guardrails in Financial Schedules
Apply clean currency, percent, integer, alignment, and #RRGGBB highlight styles—or scale raw dollars into $M display columns—understanding how Arte Sheets validates cell styles, data-validation rules, and suggest-mode permissions.
Read the guide →Financial & AccountingAI Spreadsheet Assistant Workflow: Text & Voice Formula Proposals, Bounds & Undo
Select a target range in Arte Sheets to fill or update cells, formulas, and formats via text or bounded WebRTC voice commands—understanding Before/Proposal review cards, Undo, suggestion-mode routing, and safe formula bounds.
Read the guide →Financial & AccountingAI Voice Spreadsheet Commands: Live Selection Context, Barge-In & Validated Edits
Use Arte Sheets’ bounded WebRTC voice assistant (up to 3 minutes per call) to dictate quota attainment formulas, charts, and tab navigation hands-free while client-side validation and version checks protect every cell.
Read the guide →Six Sigma & Measurement Systems AnalysisAIAG Gage R&R %StudyVar, P/T Ratio & ndc Formula
Combine Equipment Repeatability (EV), Appraiser Reproducibility (AV), and Part Variation (PV) via root-sum-of-squares to audit %StudyVar, 6-sigma Precision-to-Tolerance (P/T), and ndc = INT(1.41 * PV / GRR).
Read the guide →Healthcare & ClinicalAIMS65 Score for Upper GI Bleeding Inpatient Mortality (0–5 Points)
Calculate Saltzman's 5-point bedside AIMS65 score (Albumin < 3.0 g/dL, INR > 1.5, altered Mental status, Systolic BP <= 90 mmHg, Age > 65 years) directly from raw ED vitals and labs.
Read the guide →Global Freight Forwarding & Supply ChainAir Cargo vs Ocean LCL Chargeable Weight Formula
Calculate IATA Air Volumetric & Chargeable Weight MAX(W_gross, V_cbm * 167), Air Freight Cost, Ocean LCL W/M Revenue Tons MAX(W_gross / 1000, V_cbm), and Modal Freight Savings.
Read the guide →Healthcare & ClinicalAIR Score (Appendicitis Inflammatory Response) Calculator (0–12 Points)
Calculate Andersson’s Appendicitis Inflammatory Response (AIR) score (0–12 points) integrating CRP, graded peritoneal defense, WBC, PMN%, fever, vomiting, and RLQ pain to reduce unnecessary CT scans and negative appendectomies.
Read the guide →Aviation Finance, Airline Fleet Planning & ACMI Wet-Lease OperationsAircraft ACMI Wet-Lease MGBH Floor & PBH Reserve Formula
Calculate Airline ACMI (Aircraft, Crew, Maintenance, Insurance) Wet-Lease Billable Block Hours with Minimum Guaranteed Block Hours (MGBH) Floor, Monthly ACMI Invoice ($), Power-by-the-Hour (PBH) Engine Overhaul Reserve, and Effective Cost Per Flown Seat-Hour.
Read the guide →Flight Mechanics, Aerodynamics & Aviation SafetyAircraft Bank Load Factor, Accelerated Stall & Turn Radius
Calculate Level Coordinated-Turn Load Factor n = 1 / COS(phi), Accelerated Stall Speed V_s_bank = V_s1g * SQRT(n), Horizontal Turn Radius V_TAS^2 / (g * TAN(phi)), and Indicated Airspeed Stall Margin.
Read the guide →Flight Mechanics, Structural V-n Envelope & Aircraft DesignAircraft Wing Loading & V-n Maneuvering Corner Speed (VA)
Calculate Wing Loading W/S (N/m^2), Unaccelerated 1g Stall Speed Vs1 = SQRT((2*W/S)/(rho*CL_max)), V-n Structural Design Maneuvering Corner Speed VA = Vs1*SQRT(n_max), and Corner Dynamic Pressure.
Read the guide →Aviation Finance & Capacity PlanningAirline RASM, CASM & Break-Even Load Factor Formula
Calculate Available Seat Miles (ASM), Revenue Passenger Miles (RPM), Passenger Yield, RASM, CASM, and Break-Even Load Factor BELF = CASM / Yield.
Read the guide →Information Economics & Market DesignAkerlof Market for Lemons Adverse-Selection Cutoff Formula
Calculate the critical high-quality share q* = (S_H - B_L) / (B_H - B_L), pooling willingness-to-pay, and equilibrium trade surplus before adverse selection collapses the market.
Read the guide →Healthcare & Clinical CalculationsALBI (Albumin-Bilirubin) Score & Grade 1–3 Liver Reserve Calculator
Calculate Philip Johnson’s objective Hepatocellular Carcinoma (HCC) liver reserve score ALBI = (LOG10(Bilirubin_umolL) * 0.66) + (Albumin_gL * -0.085) and stratify ALBI Grade 1 (<= -2.60), Grade 2, and Grade 3 (> -1.39).
Read the guide →International Trade & Price TheoryAlchian-Allen "Shipping Good Apples Out" Formula
Prove Armen Alchian and William Allen’s (1964) relative-price compression theorem (P_H + f) / (P_L + f) < P_H / P_L under per-unit freight or specific charges and predict export quality upgrading.
Read the guide →Engineering & ScienceAlfvén Wave Speed (vA) & Plasma Beta (MHD Magnetic Confinement Formula)
Calculate magnetohydrodynamic Alfvén speed vA = B / SQRT(mu0 * rho) in km/s and dimensionless Plasma Beta = P_thermal / (B^2 / (2 * mu0)) for tokamak fusion reactors and solar-wind plasmas.
Read the guide →Development Economics & Welfare IndicesAlkire-Foster Multidimensional Poverty (MPI) Formula
Implement Sabina Alkire and James Foster’s (2011) dual-cutoff censoring c_i(k) = IF(c_i >= k, c_i, 0) to calculate Multidimensional Headcount H, Deprivation Intensity A, and MPI = H * A.
Read the guide →Auction Theory & Contest StrategyAll-Pay Auction Bidding & Expected Revenue Formula
Calculate Baye-Kovenock-de Vries (1996) asymmetric all-pay contest abstention probability 1 - v_2/v_1, expected expenditures, and total sunk-effort dissipation (v_2/2)*(1 + v_2/v_1).
Read the guide →Procurement & Inventory ManagementAll-Units vs Incremental Discount EOQ Formula
Compare All-Units Price-Break EOQ (step-up to Q_brk) against Incremental Marginal-Tier Discount EOQ (effective setup S + (p_0 - p_1)*Q_brk) on total annual landed cost.
Read the guide →Operations Research & Factory Physics QueueingAllen-Cuneen G/G/c Multi-Server Queue Formula
Calculate Multi-Server Utilization rho = lambda / (c * mu), Baseline Erlang-C M/M/c Waiting Time, Allen-Cuneen G/G/c Variability-Adjusted Waiting Time W_q, and Little’s Law Queue WIP L_q.
Read the guide →Business & OperationsAllen-Cunneen G/G/c Multi-Server Queue Waiting Time Approximation
Calculate expected waiting time in queue Wq and queue length Lq for general multi-server G/G/c stations (fab tool groups, CT scanners, call centers) using Allen-Cunneen variability scaling (Ca^2 + Cs^2) / 2.
Read the guide →FinancialAllowance for Doubtful Accounts & Bad Debt Expense (AR aging SUMPRODUCT)
Illustrate an aging-based allowance estimate and the adjustment from an existing unadjusted allowance balance.
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